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[From  the  22d  Annual  Report  of  the  Secretary  of  the  Mass,  State  Board  of  Agriculture,] 


OBSERVATIONS 


THE  PHENOMENA  OF  PLANT  LIFE. 


A    PAPER 


PRESENTED  TO  THB 


MASSACHUSETTS  BOAED  OP  AGEICULTUEE, 


BY   W.    S.    CLAEK, 

II 

PRESIDENT  OF  THE  MASSACHUSETTS  AGRICULTURAL  COLLEGE. 


BOSTON: 

WRIGHT   &   POTTER,    STATE   PRINTERS, 

79  MILK  STREET  (CORNER  OP  FEDERAL). 

1875. 


v\ 


PHENOMENA   OF   PLANT-LIFE. 


The  observations  concerning  "The  Circulation  of  Sap  in 
Plants,"  which  I  had  the  honor  of  presenting  before  the 
Board  of  Agriculture  at  their  last  country  meeting,  were  so 
kindly  received  at  the  time,  and  awakened  so  much  interest 
after  their  publication,  that  I  have  found  it  impossible  to 
refrain  from  further  investigations  upon  the  phenomena  of 
plant-life.  Among  the  subjects  to  which  special  attention 
has  been  directed  during  the  year,  the  following  may  be 
enumerated,  viz.  : 

First.  The  structure,  composition  and  arrangement  of  the 
winter-buds  of  hardy  trees  and  shrubs.  Specimens  for  study 
were  collected,  in  January  and  February  last,  from  one  hun- 
dred and  forty  species,  and  some  facts  of  interest  recorded. 

Second.  The  percentage  of  water  to  be  found  in  the 
branches  and  roots  of  trees  during  their  annual  period  of 
repose,  as  well  as  when  in  active  growth. 

Third.  The  phenomena  and  causes  of  the  flow  of  sap  from 
wounds  in  trees  when  denuded  of  their  foliage,  as  well  as  the 
flow  from  the  stumps  of  woody  and  herbaceous  plants  when 
cut  near  the  ground  in  summer.  In  connection  with  this 
subject,  an  attempt  has  been  made  to  determine  what  species 
flow,  how  rapidly  and  copiously,  and  under  what  circum- 
stances. 

The  pressure  exerted  by  the  sap  exuded  from  detached 
roots  of  trees  under  ground,  as  well  as  that  exhibited  upon 
gauges  placed  at  different  elevations  from  the  earth,  has  also 
been  very  carefully  observed  upon  a  number  of  species. 

The  facts  determined  are  even  more  remarkable  than  were 
noticed  last  year,  and  are  particularly  important  in  the  case 
of  the  sugar-maple. 


4  PHENOMENA  OF  PLANT-LIFE. 

Fourth.  The  structure  and  functions  of  the  bark  of  ex- 
ogenous trees,  with  special  reference  to  the  circulation  of  sap, 
the  formation  of  wood  and  the  effects  6f  girdling, — concerning 
all  which  points  many  experiments  have  been  undertaken 
with  satisfactory  results. 

Fifth.  An  attempt  has  been  made  to  measure  the  expan- 
sive force  of  growing  vegetable  tissue,  and  in  connection  with 
this  experiment  numerous  other  interesting  observations  have 
been  reached. 

These  investigations  have  been  instituted  by  myself;  but  in 
carrying  them  out,  I  have  enjoyed  the  valuable,  and,  in  many 
cases,  indispensable,  assistance  of  gentlemen  connected  with 
the  Agricultural  College,  either  as  officers  or  students.  Due 
credit  will  be  given  to  each  in  stating  the  results  of  his 
work. 

To  succeed  as  an  original  investigator  in  science,  one  must 
possess  some  of  the  noblest  qualities  of  mind  and  heart.  He 
must  be  absolutely  and  accurately  honest,  and  in  his  methods 
of  demonstration  there  must  be  no  guess-work.  He  has  need 
of  a  patience  which  is  inexhaustible,  a  zeal  and  energy  which 
never  flag,  and  a  spirit  of  devotion  to  his  work  which  utterly 
ignores  self  as  separated  from  the  object  to  be  accomplished. 
He  must  also  have  a  well-disciplined  mind,  and  skill  in  the 
use  of  books  and  apparatus.  To  produce  such  men,  who 
shall,  at  the  same  time,  be  familiar  with  all  the  great  princi- 
ples and  problems  of  agriculture,  is  the  highest  possible 
achievement  of  our  College.  One  such  graduate  will  do  more 
for  the  advancement  of  the  art,  and  the  honor  of  the  profes- 
sion and  the  benefit  of  mankind,  than  would  a  host  of  mere 
farm-apprentices  possessed  only  of  manual  skill  and  a  knowl- 
edge of  simple,  routine  practice,  however  well  adapted  to  any 
particular  locality  or  style  of  farming. 

I  am  well  aware  that  there  are  persons  who  hold  a  respect- 
able position  in  society,  and  yet  are  so  ignorant  as  to  regard 
with  contempt  all  efforts  at  scientific  research.  They  ridicule 
the  attachment  of  gauges  to  trees,  and  the  harnessing  of 
squashes,  and  the  microscopic  and  chemical  analysis  of  plants, 
as  of  no  earthly  use,  except,  perhaps,  to  gratify  an  idle 
curiosity.  But  how  shall  agriculture  be  improved  without 
the  application  to  it  of  the  principles  of  science  ;  and  how 


PHENOMENA  OF  PLANT-LIFE.  5 

shall  these  be  applied  unless  they  are  discovered ;  and  how 
shall  they  be  known,  if  they  are  not  sought?  In  no  way  can 
the  wealth  of  the  world  be  increased  so  surely  as  by  the 
liberal  endowment  of  institutions  for  the  special  purpose  of 
securing  experiments  in  all  departments  of  science  which  have 
a  direct  connection  with  agriculture,  especially  in  chemistry 
and  in  animal  and  vegetable  physiology.  When  we  consider 
that,  to  observe  the  transit  of  Venus  during  the  present 
month,  expeditions  have  been  sent  to  different  parts  of  the 
earth,  at  a  cost  of  more  than  a  million  of  dollars,  we  may,  at 
least,  hope  that  scientific  observations  upon  things  nearer 
home,  and  having  more  to  do  with  e very-day  life,  will  soon 
be  appreciated  and  supported. 

We  are  told  that  when  the  illustrious  scientist,  Faraday, 
who  devoted  his  life  to  original  research,  was  asked  by  some 
practical  individual  what  was  the  use  of  one  of  his  famous 
discoveries,  he  answered  him  by  propounding  another  equally 
pertinent  question,  namely,  "What  is  the  use  of  a  baby?" 
The  possible  results  are  in  both  cases  of  transcendent  moment, 
but  in  neither  can  they  be  foretold.  It  is  enough  to  know 
that  every  new  truth  is  an  open  door  to  some  further  dis- 
covery and  to  some  useful  invention. 

It  has  been  well  said  that  it  is  comparatively  easy  to  know 
something  about  everything,  but  very  difficult  to  learn  every- 
thing about  anything.  Remembering  that  we  are  enveloped 
by  inexplicable  mysteries,  and  that  abundant  material  for 
investigation  lies  everywhere  about  us,  we  have  attempted  to 
study  that  most  familiar  plant,  the  squash, — and  the  results 
have  far  surpassed  our  most  sanguine  expectations. 

The  particular  species  selected  for  observation  is  named 
Cucurbita  maxima,  and  the  variety  is  called,  by  Gregory, 
the  mammoth  yellow  Chili.  It  is  said  to  be  a  native  of  the 
Levant,  and  to  have  been  introduced  into  England  in  1547. 
It  is  sometimes  called  the  French  pumpkin,  and  its  fruit 
readily  attains  a  weight  of  one  hundred  and  fifty  pounds. 
One  has  been  grown  in  England  which  weighed  two  hundred 
and  forty-six  pounds. 

Squashes  indigenous  to  tropical  America  were  cultivated 
by  the  Indians  long  before  the  occupation  of  this  continent 
by  the  whites. 


6  PHENOMENA  OF  PLANT-LIFE. 

The  Oucurbitacece  are  a  small,  but  very  useful  order  of  the 
vegetable  kingdom,  numbering  about  three  hundred  and  fifty 
species,  which  are  chiefly  natives  of  warm  regions.  The 
most  valuable  species  are  the  squash,  the  pumpkin,  the 
cucumber,  the  water-melon,  the  musk-melon  and  the  gourd, 
of  all  which  there  are  numerous  varieties. 

These  plants  are  generally  herbaceous,  and  trailing  or 
climbing  by  means  of  tendrils.  Their  stems,  leaf-stalks, 
tendrils  and  fruits  are  often  hollow,  and  their  tissues  very 
soft  and  succulent. 

The  flowers  are  usually  large,  and  either  yellow  or  white, 
and  of  two  or  three  sorts  on-  the  same  plant.  The  fruit  is 
commonly  a  pepo,  the  structure  of  which  is  familiar  to  all. 

The  following  considerations  suggested  the  idea  of  experi- 
menting with  the  mammoth  squash  : 

First.  It  is  a  well-known  fact  that  beans,  acorns  and  other 
seeds  often  lift  comparatively  heavy  masses  of  earth  in  forcing 
their  way  up  to  the  light  in  the  process  of  germination. 

Second.  We  have  all  heard  how  common  mushrooms  have 
displaced  flagging- stones,  many  years  since,  in  Basingstoke, 
and,  more  recently,  in  Worcester,  England.  In  the  latter 
case,  only  a  few  weeks  ago,  a  gentleman  noticing  that  a  stone 
in  the  walk  near  his  residence  had  been  disturbed,  went  for 
the  police,  under  the  impression  that  burglars  were  preparing 
some  plot  against  him.  Upon  turning  up  the  stone,  which 
weighed  eighty  pounds,  the  rogues  were  discovered  in  the 
shape  of  three  giant  mushrooms.  * 

Third.  Bricks  and  stones  are  often  displaced  by  the  growth 
of  the  roots  of  shade-trees  in  streets.  Cellar  and  other  walls 
are  frequently  injured  in  a  similar  way. 

Fourth.  There  is  a  common  belief  that  the  growing  roots 
of  trees  frequently  rend  asunder  rocks  on  which  they  stand, 
by  penetrating  and  expanding  within  their  crevices. 

Having  never  heard  of  any  attempt  to  measure  the  expan- 
sive force  of  a  growing  plant,  we  determined  to  experiment 
in  this  direction.  . 

We  were  surprised,  last  year,  in  testing  the  pressure 
exerted  by  the  sap  of  various  trees,  to  find  that  a  black  birch- 
root  detached  from  the  tree,  was  able  to  force  water  to  the 
height  of  eighty-six  feet.  We  were  therefore  somewhat  pre- 


PHENOMENA  OF  PLANT-LIFE.  7 

pared  for  an  exhibition  of  considerable  power,  but  the  results 
of  our  trials  have,  nevertheless,  been  most  astonishing. 

At  first,  we  thought  of  trying  the  expansive  force  of  some 
small,  hard,  green  fruit,  such  as  a  hickory-nut  or  a  pear,  but 
the  expansion  was  so  slow,  and  the  attachment  of  the  fruit 
to  the  tree  so  fragile,  that  this  idea  was  abandoned.  The 
squash,  growing  on  the  ground  with  great  rapidity  and  to  an 
enormous  size,  seemed,  on  the  whole,  the  best  fruit  for  the 
experiment. 

Accordingly,  seeds  having  been  obtained  from  Mr.  J.  J.  H. 
Gregory,  of  Marblehead,  they  were  planted  on  the  first  of 
July  in  one  of  the  propagating  pits  of  the  Durfee  Plant-House, 
where  the  temperature  and  moisture  could  be  easily  con- 
trolled. A  rich  bed  of  compost  from  a  spent  hot-bed  was 
prepared,  which  was  four  feet  wide,  fifty  feet  long,  and  about 
six  inches  in  depth.  Here,  under  the  fostering  care  of  Prof. 
Maynard,  the  seeds  germinated,  the  vine  grew  vigorously, 
and  the  squash  lifted  in  a  most  satisfactory  manner. 

Never  before  has  the  development  of  a  squash  been  observed 
more  critically,  or  by  a  greater  number  of  people.  Many 
thousands  of  men,  women  and  children,  from  all  classes  of 
society,  and  of  various  nationalities,  and  from  all  quarters  of 
the  earth,  visited  it.  Mr.  D.  P.  Penhallow  watched  with  it 
several- days  and  nights,  making  hourly  observations.  Prof. 
H.  W.  Parker  was  moved  to  write  a  poem  about  it,  and 
Prof.  J.  H.  Seelye  declared  that  he  positively  stood  in 
awe  of  it. 

Vegetable  growth  consists  in  the  development  of  the  several 
parts  of  a  plant,  according  to  a  definite,  predetermined  plan 
as  regards  the  form,  size  and  other  characteristics  of  each 
species.  It  results  from  the  activity  of  a  certain  peculiar 
inherent  force,  called  life.  Under  the  influence  of  this  force, 
stimulated  to  action  by  heat  and  light,  plants  absorb,  digest 
and  assimilate  mineral  matter,  converting  it  into  the  various 
organic  substances  which  enter  into  their  composition.  Ex- 
amined under  the  microscope,  all  parts  of  plants  are  found 
to  consist  primarily  of  closed  cells,  cohering  into  masses  of 
various  forms  and  containing  protoplasm. 

Growth  is  caused  by  the  increase  of  cells  in  number  and  in 
size.  In  a  growing  portion  of  a  plant,  as  at  the  tip  of  the 


8  PHENOMENA  OF  PLANT-LIFE. 

stem,  the  first-formed  cells  are  subdivided,  and  then  the  sub- 
divisions enlarge  to  the  normal  size,  and  this  process  goes  on 
while  growth  continues.  All  vegetable  material  is  primarily 
formed  in  the  leaves  or  green  parts  of  ordinary  plants,  and, 
by  a  vital  process  of  circulation,  is  transferred  in  a  liquid 
form  to  its  proper  destination. 

The  seed  is  a  minute  plant,  consisting  of  a  radical  or  little 
root,  a  terminal  bud  called  the  plumule,  and  one  or  more 
seed-leaves,  all  snugly  packed  away  in  a  shell  for  safe  keep- 
ing during  transportation.  In  order  that  the  sprouting  plant- 
let  may  be  able  to  get  hold  of  the  earth  for  its  water  and 
mineral  supplies,  and  have  substance  enough  to  reach  up  into 
the  light  and  air  where  it  is  to  find  its  future  carbon,  the  seed- 
leaves,  or  cotyledons,  are  formed  of  very  condensed  and  com- 
plex materials, —  such  as  oil,  sugar,  starch  and  albuminoids. 
The  requisite  conditions  of  germination  for  a  sound,  living 
seed  are  air,  water,  and  a  moderate  degree  of  heat.  The 
time  intervening  between  the  planting  of  a  seed  and  the 
appearance  of  the  root  varies  from  a  few  hours  to  many 
months.  It  may  be  hastened  in  some  cases  by  scalding  the 
seed  for  a  few  minutes  in  hot  water,  or  by  the  judicious  use 
of  a  solution  of  camphor,  sal-ammoniac,  or  oxalic  acid.  The 
cotyledons  of  the  squash-seed  are  pushed  up  into  the  air, 
where  they  expand  and  thicken,  assume  a  green  color,  and  for 
a  time  perform  the  functions  of  true  leaves. 

The  root  is  the  first  part  of  a  plant  to  grow,  and  develops 
downward,  as  if  affected  by  the  force  of  gravity.  Light 
neither  hurts  nor  helps  the  root,  but  water  is  essential  to  its 
life,  and  for  this  it  penetrates  the  soil  in  every  direction.  It 
is  the  special  function  of  the  root  to  absorb  and  furnish  to  the 
rest  of  the  plant,  water,  nitrogenous  matter,  and  such  soluble 
minerals  as  each  species  requires  for  its  use.  For  this  pur- 
pose it  is  admirably  adapted  by  its  peculiar  structure,  sub- 
stance and  mode  of  increase.  The  older  portion  of  roots 
serves  to  sustain  the  stem  and  hold  it  in  place,  and  also  acts 
as  a  reservoir  of  supplies  to  the  plant.  The  younger  roots 
usually  branch  off  in  an  irregular  manner,  and  elongate  by  the 
multiplication  of  cells  near  their  extremities.  The  tips  of 
roots  are  usually  very  minute  fibres  of  exceedingly  delicate 
tissue,  which  insinuate  themselves  into  the  pores  of  the  soil, 


PHENOMENA  OF  PLANT-LIFE.  9 

and  then,  by  the  expansive  power  of  growth,  enlarge  these 
capillary  channels  to  any  required  size. 

Roots  of  ordinary  plants  grow  most  freely  in  a  loose,  well- 
drained  soil,  containing  the  essential  elements  of  plant-food  in 
a  soluble  form.  They  absorb  their  water  from  the  surface  of 
the  molecules  of  the  soil,  to  which  they  attach  themselves  by 
very  minute,  cellular  papillae,  called  root-hairs.  These  hairs 
are  much  more  numerous  in  a  soil  moderately  dry  than  in 
one  which  is  wet  and  heavy.  The  most  vigorous  plants  have 
the  largest  number  and  greatest  extent  of  roots.  Hence 
the  importance  of  deep  and  thorough  tillage  in  preparing  the 
ground  for  crops.  The  growth  of  a  plant  depends  chiefly 
upon  the  amount  of  water  which  is  exhaled  by  its  leaves,  and 
this  necessarily  depends  upon  the  supply  furnished  by  the 
the  roots.  The  folly  of  ploughing  between  rows  of  corn,  or 
other  plants,  after  their  roots  have  spread  widely  through  the 
soil,  is  self-evident.  Prof.  L.  B.  Arnold  says  he  has  known 
the  maturing  of  a  corn-crop  postponed  ten  days  by  ploughing 
it  at  the  last  hoeing. 

The  penetrating  power  and  tendency  of  roots  is  well  illus- 
trated in  the  case  of  an  apple-tree  on  the  College  farm,  which 
forced  its  roots  down  through  a  mass  of  coarse  gravel  eight 
feet,  to  obtain  a  supply  of  water.  The  stones  were  about  the 
size  of  hens'  eggs,  and  so  closely  packed  by  the  waters  of  the 
drift  period  which  deposited  them,  that  the  cylindrical  form 
of  the  roots  was  entirely  destroyed.  The  growing  tissues 
pressed  themselves  into  every  crevice  so  as  actually  to 
surround  and  enclose  the  adjoining  pebbles.  (Fig.  17.)  A 
similar  root  of  an  elm  was  recently  dug  up  in  Westfield,  Mass., 
and  presented  to  the  College  museum  by  Mr.  B.  H.  Averell. 
Prof.  Stockbridge,  last  fall,  washed  out  a  root  of  common  clo- 
ver, one  year  old,  growing  in  the  alluvial  soil  near  the  Connec- 
ticut River,  and  found  that  it  descended  perpendicularly  to  the 
depth  of  eight  feet.  Mr.  Mechi,  of  Tiptree  Hall,  England, 
tells  us  that  the  reason  clover  is  usually  so  short-lived,  is  the 
fact  that  the  lower  roots  are  either  unable  to  penetrate  the 
subsoil  or  to  find  in  it  the  requisite  supplies  of  food.  He 
also  states  that  his  neighbor,  Mr.  Dixon,  of  Riven  Hall,  dug 
a  parsnip  which  measured  thirteen  feet  six  inches  in  length, 
but,  unfortunately,  was  broken  at  that  depth. 


10  PHENOMENA  OF  PLANT-LIFE. 

The  roots  of  lucerne  often  penetrate  to  the  depth  of  more 
than  twenty  feet,  while  the  tap-roots  of  trees,  continuing 
to  grow  for  a  long  period,  descend  still  further.  A  Brit- 
ish officer  in  India  reports  that  the  root  of  a  leguminous 
tree — the  Prosopis  spicigera — is  often  dug  for  economical  pur- 
poses, and  that  he  has  seen  an  excavation  sixty-nine  feet  deep 
made  for  such  a  root  without  reaching  its  lower  extremity. 
The  roots  of  trees  are  well  known  to  extend  in  a  horizontal 
direction  to  surprising  distances,  and  to  exert  a  very  delete- 
rious influence  on  crops  in  their  vicinity.  The  living  roots 
of  an  elm,  in  Amherst,  were  found  in  abundance  at  a  distance 
of  seventy-five  feet  from  the  trunk,  which  was  just  the  height 
of  the  tree.  It  has  recently  been  stated  in  "The  Field," 
an  English  paper,  that  the  roots  of  an  elm  were  found  to 
obstruct  a  tile-drain  which  was  .four  hundred  and  fifty  feet 
from  the  tree. 

But  our  squash-vine  affords  the  most  astonishing  demonstra- 
tion of  all  that  has  been  said  about  root-development.  Grow- 
ing under  the  most  favorable  circumstances,  the  roots  attained 
a  number  and  an  aggregate  length  almost  incredible.  The 
primary  root  from  the  seed,  after  penetrating  the  earth  about 
four  inches,  terminated  abruptly  and  threw  out  adventitious 
branches  in  all  directions.  In  order  to  obtain  an  accurate 
knowledge  of  their  development,  the  entire  bed  occupied  by 
them  was  saturated  with  water,  and,  after  fifteen  hours, 
numerous  holes  were  bored  through  the  plank-bottom,  and 
the  earth  thus  washed  away.  After  many  hours  of  most 
patient  labor,  the  entire  system  of  roots  was  cleaned  and 
spread  out  upon  the  floor  of  a  large  room,  where  they  were 
carefully  measured.  The  main  branches  extended  from  twelve 
to  fifteen  feet,  and  their  total  length,  including  branches,  was 
more  than  two  thousand  feet.  At  every  node,  or  joint,  of  the 
vine,  was  also  produced  a  root.  One  of  these  nodal  roots  was 
washed  out  and  found  to  be  four  feet  long,  and  to  have  four 
» hundred  and  eighty  branches,  averaging,  with  their  branch- 
lets,,  a  length  of  thirty  inches,  making  a  total  of  more  than 
twelve  hundred  feet.  As  there  were  seventy  nodal  roots, 
there  must  have  been  more  than  fifteen  miles  in  length 
on  the  entire  vine.  There  were  certainly  more  than  eighty 
thousand  feet ;  and  of  these,  fifty  thousand  feet  must  have 


PHENOMENA  OF  PLANT-LIFE.  11 

been  produced  at  the   rate  of  one  thousand   feet  , or  more  ^ 
per  day. 

</i^          1     ^ 

Now,  it  has  been  said,  that  corn  may  be  heard^ta  grow-4nr> 
a  still,  warm  night,  and  it  has  been  proved  that  a  rc\ot  of  corn 
will  elongate  one  inch  in  fifteen  minutes.  But  here  aise  twelve 
thousand  inches  of  increase  in  twenty-four  hours.  What 
lively  times  in  the  soil,  where  such  vital  force  is  at  work! 
The  wonder  is,  we  do  not  hear  the  building  of  these  roots  as 
it  goes  on. 

But  in  addition  to  the  movements  caused  by  the  increase  of 
the  roots  among  the  particles  of  the  soil,  we  should  remember 
that  solution,  chemical  affinity,  diffusion  and  capillarity,  as 
well  as  the  absorption  of  the  feeding  rootlets,  are  incessantly 
at  work  beneath  the  surface  of  the  silent  earth.  With  what 
amazement  should  we  behold  the  development  of  a  crop  upon 
a  fertile  field,  if  we  could  but  see  with  our  eyes  the  things 
which  are  known  to  transpire  ! 

Let  us  next  consider  some  peculiarities  of  plant-growth 
which  were  exhibited  in  the  development  of  the  squash-vine, 
with  its  appendicular  organs — the  leaves  and  the  tendrils, 
and  its  reproductive  organs — the  flowers  and  the  fruit. 

The  peculiar  feature  of  the  vegetable  stem  is  the  bud,  by 
which  it  is -always  terminated,  even  in  the  seed.  A  bud  is 
an  aggregation  of  delicate  cells,  filled  with  protoplasm,  and 
endowed  with  special  vitality.  Sometimes  it  is  very  minute 
and  simple  in  structure,  and  sometimes  large  and  complicated. 
As  the  stem  elongates,  it  usually  produces,  at  regular  inter- 
vals, leaves,  in  the  axils  of  which  are  formed  buds,  which,  in 
growing,  become  the  terminal  buds  of  branches.  The  places 
where  leaves  are  borne  are  called  nodes,  and  the  spaces  on  the 
stem  between  these  are  styled  internodes.  Every  species  of 
plant  has  a  definite  law  for  the  arrangement  of  its  leaves. 
Our  squash  produced  one  leaf  at  each  node,  and  all  the  leaves 
were  arranged  in  two  rows  on  opposite  sides  of  the  stem. 
The  vital  force  in  the  tip  of  the  vine  was  very  active  and 
vigorous,  and  displayed  its  power  in  the  constant  organization 
of  new  nodes.  Thus,  when  we  examined  the  terminal  inch 
of  the  vine,  we  found  no  less  than  twenty-five  young  leaves, 
and  in  the  axils  of  these  twenty-five  flowers,  including  five 
young  squashes,  twenty-five  branching  tendrils,  and  twenty- 


12  PHENOMENA  OF  PLANT-LIFE. 

five  buds  for  lateral  branches.  These  were  continually  repro- 
duced, so  that  when  the  vine  was  growing  nine  inches  a  day, 
as  well  as  after  it  had  developed  one  hundred  nodes,  the  num- 
ber was  always  about  the  same.  All  parts  of  the  vine  and 
its  appendages  increased  with  marked  uniformity.  Back  of 
the  first  inch,  which  may  be  regarded  as  the  terminal  bud, 
about  six  nodes  were  developing  at  the  same  time.  The 
growth  was  most  rapid  in  the  terminal  portion  of  each  node, 
and  the  leaves  were  not  modified  particularly  in  form  during 
the  period  of  development.  The  lengthening  of  the  vine  pro- 
ceeded somewhat  irregularly,  varying  from  nothing  to  nine- 
sixteenths  of  an  inch  per  hour.  It  was  usually  less  between 
midnight  and  sunrise  than  at  other  hours. 

The  longest  growth  of  the  main  vine  in  twenty-four  hours 
was  observed  August  15th  and  16th,  from  7  A.  M.  to  7  A.  M., 
and  amounted  to  nine  inches.  The  laterals  were  removed  when 
two  or  three  feet  in  length.  The  total  extent  of  the  main 
vine  was  fifty-two  feet,  and  the  number  of  nodes  Tvas  one  hun- 
dred. At  each  node  of  the  fully-developed  vine  were  found  a 
large  leaf;  a  long,  branching  tendril,  resembling  the  veins  of  a 
leaf,  without  the  intervening  cellular  tissue  ;  a  staminate  flower 
on  a  long  stalk,  or  a  pistillate  flower  on  a  short  stalk ;  a 
lateral  branch,  and,  on  the  under  side  of  the  vine,  a  long, 
branching  root.  The  function  of  this  root  was  evidently  to 
supply  water  to  the  leaf  above  it,  and  its  development,  of 
course,  depended  chiefly  upon  the  nutrient  material  elaborated 
by  this  leaf.  These  nodal  roots  not  only  furnished  a  much 
larger  feeding-ground  for  the  plant,  but  saved  an  immense 
amount  of  mechanical  work  in  reducing  the  distances  through 
which  the  crude  and  elaborated  saps  must  be  carried. 

The  largest  leaves  of  the  squash-vine  were  nearly  circular, 
and  slightly  lobed,  with  a  diameter  of  two  feet  and  a  half, 
and  a  superficial  area  of  about  seven  hundred  square  inches. 
The  leaf-stalks  were  hollow,  two  feet  in  length,  and  curiously 
marked  with  vertical  striae,  alternately  light  and  dark  in  color. 
The  light  lines  were  found  to  contain  bundles  of  fibro-vascular 
tissue,  while  the  dark  ones  were  simple  cellular  tissue,  con- 
taining chlorophylT 

The  special  functions  of  the  leaf  are  to  absorb  carbonic  acid 
from  the  atmosphere,  and,  by  a  process  of  digestion,  form 


PHENOMENA  OF  PLANT-LIFE.  13 

from  its  carbon  and  the  elements  of  water,  the  soluble  starch 
aud  sugar  out  of  which  the  tissues  of  the  plant  are  con- 
structed ;  to  exhale  the  surplus  water  of  the  crude  sap,  and 
thus  aid  in  its  ascension  from  the  soil  and  the  roots  ;  to  exhale 
the  oxygen  set  free  in  the  process  of  digestion,  and  thus  to 
purify  the  air  for  the  respiration  of  animals ;  and,  finally,  to 
exhale,  at  night  especially,  the  surplus  carbonic  acid  liberated 
within  the  plant  in  the  process  of  vegetable  respiration,  which 
appears  to  be  as  necessary  and  constant  as  that  of  animals. 
It  seems  also  most  probable  that  the  albuminoids,  or  proto- 
plasmic substances,  are  first  produced  in  the  leaf,  and  thence 
transferred  to  the  various  localities,  where  they  are  needed  in 
the  process  of  growth. 

To  facilitate  and  control  the  absorption  and  exhalation  of 
gases  and  aqueous  vapor,  leaves  are  furnished  with  breath- 
ing-pores, or  stomates,  which  open  under  the  stimulus  of 
light  and  moisture,  and  close  in  darkness,  or  when  scantily 
supplied  wi?h  water.  These  stomates  are  about  twice  as 
numerous  on  the  under  as  on  the  upper  -side  of  the  squash- 
leaf,  and  the  total  number  is  about  one  hundred  and  fifty  thou- 
sand to  the  square  inch,  or  more  than  one  hundred  millions 
on  each  large  leaf.  One  leaf  of  the  great  water-lily,  Victoria 
regia,  nine  feet  in  diameter,  contains  about  twenty-four  hun- 
dred millions  of  stomates  on  its  upper  side,  and  none  on  its 
under  surface,  where  they  would  be  useless. 

During  the  past  year  much  has  been  written  and  said  about 
carnivorous  plants,  which  catch  great  numbers  of  insects  for 
the  apparent  purpose  of  feeding  upon  them.  When  a  fly 
alights  on  the  leaf  of  a  Dionoea,  the  two  halves  close  upon  it 
and  hold  it  last  until  consumed,  when  they  open  for  another. 
The  leaf  of  a  species  of  Drosera,  in  New  Jersey,  is  said  to 
have  the  power  of  moving  towards  an  insect,  fastened  within 
half  an  inch  of  it,  and  feeding  upon  it.  The  pitcher-shaped 
leaves  of  Sarracenia  variolaris  not  only  seem  to  possess  the 
power  of  enticing  insects  to  climb  from  the  ground  to  the 
inside  of  their  pitchers,  by  secreting  a  vertical  line  of  honey 
on  the  outside,  and  also  a  line  around  the  edge  of  the  cup, 
but  they  prevent  their  escape  by  an  ingenious  arrangement  of 
hairs,  which  continually  force  them  downward  as  they  attempt 
to  fly  out.  When  they  thus  reach  the  bottom  of  their  prison, 


14  PHENOMENA  OF  PLANT-LIFE. 

they  come  in  contact  with  a  fluid  which  first  paralyzes  them, 
and  then  hastens  their  decay  and  absorption. 

Not  less  wonderful  are  the  instinctive  movements  by  which 
climbing  plants  seek  for,  and  attach  themselves  to,  a  support. 
Twining  vines,  like  the  hop,  the  bean,  and  the  morning-glory, 
exhibit  a  revolving  movement  of  their  extremities,  until  they 
come  in  contact  with  some  object  around  which  to  coil.  Each 
species  has  its  own  peculiar  direction,  from  which  most  of 
them  never  vary.  A  few,  like  the  hop,  wind  from  the  right 
upward  towards  the  left,  moving  like  the  hands  of  a  watch, 
but  most,  like  the  bean,  move  in  an  opposite  direction.  The 
squash,  however,  is  not  a  twining  plant,  but  climbs  by  means 
of  tendrils.  Nevertheless,  the  tip  of  a  growing  vine  revolves 
continually  from  left  over  to  right,  in  evident  search  for  a 
support. 

Mr.  J.  J.  H.  Gregory  informs  us,  that  if  a  shingle  be  set 
into  the  ground  near  the  tip  of  a  growing  squash-vine,  it  will, 
in  a  day  or  two,  be  seen  turning  towards  it ;  and  that,  if  the 
shingle  be  removed  to  the  opposite  side,  the  direction  of  the 
vine  will  again  be  changed.  He  also  states  that  he  has 
observed  a  squash-vine,  after  running  along  on  the  ground  ten 
or  twelve  feet,  and  then  passing  under  the  branches  of  a  tree 
which  were  four  feet  above  it,  to  stop  and  turn  upward  towards 
he  branches.  After  growing  in  this  direction  till  it  could  no 
longer  sustain  itself,  the  vine  fell  to  the  ground ;  but  instead 
of  proceeding  horizontally,  it  again  rose  into  the  air,  again  to 
fail.  A  third  effort  was  made  before  the  plant  was  willing  to 
give  up  and  trail  humbly  on  the  earth. 

The  end  of  the  vine  under  observation  was  constantly 
elevated  to  the  sash-bars  and  glass  above  it,  sometimes  to  the 
height  of  two  feet,  and  as  it  increased  in  length,  was  pushed 
along  against  them.  The  extent  and  velocity  of  the  terminal 
motion  were  doubtless  greatest  in  August,  when  growth  was 
most  rapid.  The  record,  however,  was  made  in  November. 
The  time  occupied  in  each  revolution  was  variable,  and  the 
long  diameter  of  the  ellipse  described,  which  was  horizontal, 
measured  about  two  inches. 

The  tendrils  of  the  squash- vine  were  produced  at  the  nodes, 
and  the  main  stalk  was  hollow  and  divided  into  several 
branches  at  a  point  three  or  four  inches  distant  from  the  vine. 


PHENOMENA  OF  PLANT-LIFE.  15 

These  branches  spread  out  in  various  directions,  and  attained 
a  length  of  six  or  eight  inches.  Each  branch  gradually 
straightened  out  from  the  coil  in  which  it  first  appeared,  and 
increased  in  length.  When  about  two-thirds  developed,  it 
began  to  revolve,  so  that  its  hooked  tip  described  an  ellipse 
several  inches  in  diameter.  Its  revolution  was-  made  by  a 
series  of  bendings,  in  such  a  way  as  not  to  twist  itself.  The 
tendrils  moved  in  the  same  direction  with  the  tip  of  the  vine, 
but  somewhat  irregularly  both  as  to  time  and  to  the  figure 
described.  During  the  day,  the  ellipse  was  broad,  and  at 
night,  long  and  narrow.  Usually,  the  motion  was  scarcely 
perceptible  to  the  eye,  but  sometimes  it  moved  two  inches  in 
five  minutes.  The  average  time  of  revolution  in  November 
was  about  three  hours.  If  touched  by  the  finger  on  the 
sensitive  or  inner  side,  the  tendril  bent  towards  the  place 
where  the  finger  was,  and,  not  finding  it,  straightened  itself 
again.  If,  however,  it  came  in  contact  with  any  object  to 
which  it  could  cling,  it  bent  at  the  point  of  contact,  and  the 
concave  curvature  extended  along  the  inside  of  the  branch, 
until  the  extremity  was  wound  closely  around  the  support. 
Other  branches  would,  also,  fasten  to  the  same  object,  if  pos- 
sible. The  tendril,  thus  attached,  increased  in  size  and  firm- 
ness, and  soon  coiled  upon  itself  in  a  double  reversed  spiral, 
so  as  to  exert  a  strain  on  the  support.  All  the  branches 
having  done  this,  they  pull  together  and  must  fail  together, 
if  at  all. 

Another  most  obvious  benefit  derived  from  this  double 
spiral,  is  the  elasticity  of  the  fastening,  which  greatly  dimin- 
ishes the  danger  of  rupture  by  violence.  If  the  tendrils 
of  the  squash  failed  in  finding  a  support,  the  branches  then 
coiled  upon  themselves,  and  the  main  stalk  often  turned  back 
along  the  vine. 

The  habits  of  climbing  plants  have  been  studied  by  Mr. 
Charles  Darwin  and  others ;  but  this  field  for  research  is  by 
no  means  exhausted. 

The  tendrils  of  the  grape  vine  are  not  very  sensitive,  but 
fasten  themselves  very  firmly  to  a  suitable  support.  The 
tendrils  of  the  Coboea  scandens  are  long,  branching,  and 
tipped  with  woody  claws.  They  are  extensions  of  the  petiole 
of  a  compound  leaf,  revolve  actively,  and  attach  themselves 


16  PHENOMENA  OF  PLANT-LIFE. 

in  a  most  marvellous  manner.  When  a  revolving  branch  has 
found  a  support,  it  contracts  so  as  to  bring  its  extremities  in 
contact  with  it.  The  other  branches  seek  the  same  object, 
and,  as  they  are  sensitive  on  all  sides,  they  fail  in  many  cases 
to  secure  a  firm  attachment  with  their  claws.  They  therefore 
detach  themselves  from  their  support,  one  at  a  time  in  suc- 
cession, twist  so  as  to  bring  their  claws  into  the  proper  direc- 
tion, and  then  again  make  fast. 

It  is  well  known  that  most  plants  grow  toward  the 
strongest  light ;  but  climbing  plants  are  sometimes  excep- 
tions. English  ivy  turns  its  young  shoots  away  from  the 
light  in  order  that  they  may  come  in  contact  with  dark 
objects, — such  as  rocks  and  trunks  of  trees, — to  which  they 
then  attach  themselves  by  short  roots.  The  tendrils  of  the 
Virginia  creeper,  or  woodbine,  are  among  the  most  wonder- 
ful. They  grow  away  from  the  light,  and  send  their  branches 
into  crevices  of  old  bark  and  rocks.  Sometimes  such  tendrils 
are  said  by  Mr.  Darwin  to  actually  show  a  power  of  choosing 
one  place  of  attachment  in  preference  to  another,  by  penetrat- 
ing a  cavity  and  then  withdrawing  to  seek  a  more  satisfactory 
one.  As  soon  as  the  tendrils  of  the  creeper  find  a  support, 
the  branches  spread  out  their  tips  and  press  them  against  it. 
Little  pads  of  hard  cellular  tissue  are  now  developed  at  the 
points  of  contact,  and  the  tendril  coils  on  itself  and  becomes 
very  tough  and 'woody.  At  the  end  of  the  first  season  it 
dies,  but  remains  firmly  fixed  to  its  support  for  many  years. 
Mr.  Darwin  found  one,  which,  though  ten  years  old,  was  not 
detached  by  a  weight  of  ten  pounds  from  the  wall  to  which  it 
had  adhered. 

The  chemical  constitution  of  the  squash-vine  under  obser- 
vation has  not  yet  been  determined ;  but  its  anatomical 
structure,  in  all  its  parts,  may  be  readily  understood  by  an 
examination  of  the  figures  appended  to  this  paper,  which  are 
accompanied  by  detailed  explanations.  The  vine,  the  petioles, 
the  flower-stalks,  the  tendrils  and  the  fruits  were  hollow,  so 
that  about  thirty  per  cent,  of  the  apparent  size  was  simply 
air.  The  greater  proportion  of  the  remainder  was  water,  so 
that  less  than  ten  per  cent,  of  the  entire  volume  was  solid, 
dry  material.  The  large,  yellow  flowers  were  arranged  in 
regular  succession,  one  at  each  node.  A  female  flower  was 


PHENOMENA  OF  PLANT-LIFE.  17 

usually  succeeded  by  four  males,  so  that  on  such  a  vine  a 
squash  would  be  produced  at  every  fifth  node,  if  every  one 
should  set,  which,  however,  never  happens.  The  impregna- 
tion of  the  ovules  within  the  ovary  of  the  female  flower 
requires  the  deposition  of  pollen-grains  from  the  anther-cells 
of  the  male  flower  upon  the  stigma  of  the  former  under  favor- 
able circumstances.  The  stigmatic  surface  must  be  in  a  proper 
condition  to  retain  and  develop  the  pollen,  which  must  be  in 
a  perfect  state.  Bright,  warm  weather  will  doubtless  aid  in 
the  process,  though  many  observations  are  still  needed  con- 
cerning this  subject.  The  pollen-grains  of  the  squash  are 
large  and  rough,  and  of  a  spherical  form,  and  consist  of  an 
outer  and  inner  coating  of  membrane  filled  with  a  proto- 
plasmic fluid.  In  the  outer  coating  is  a  minute  orifice, 
through  which,  when  moistened  by  the  saccharine  secretion 
of  the  stigma,  the  inner  coating  protrudes  as  a  microscopic, 
structureless  tube,  which  pushes  its  Way  through  the  tissues 
of  the  style  and  ovary  until  it  reaches  the  embryo-sac  of  an 
ovule,  which  may  then  become  a  perfect  seed.  This  contact 
of  the  pollen-tubes  with  the  ovules  is  essential  to  the  setting 
of  every  squash.  The  transfer  of  the  pollen-grains  to  the 
stigmas  is  usually  accomplished  by  insects  whicb  fly  from 
flower  to  flower  in  pursuit  of  food.  It  may,  also,  be  done 
artificially,  and  there  is  reason  to  believe  that  the  crop 
of  squashes,  melons  and  cucumbers  might  often  be  largely 
increased  by  attention  to  thi*  matter  in  out-door  cultivation. 
When  grown  under  glass,  fertilization  must  always  be  effected 
by  artificial  means. 

The  pistillate,  or  female  flower,  on  the  twenty-first  node  of 
the  growing  vine,  was  artificially  impregnated  with  pollen 
from  a  staminate,  or  male  flower,  on  the  first  of  August. 
The  young  squash  immediately  began  to  enlarge,  and-,  on  the 
fifteenth  of  the  same  month,  measured  twenty-two  inches  in 
circumference ;  on  the  sixteenth,  twenty-four  inches,  and  on 
the  seventeenth,  twenty-seven.  Though  the  rind  of  the  young 
fruit  was  very  soft,  it  was  now  determined  to  confine  it  in 
such  a  way  as  to  test  its  expansive  power.  In  doing  this, 
great  care  was  taken  to  preserve  the  health  and  soundness  of 
every  part  of  the  squash,  and  to  expose  at  least  one-half  of 
its  surface  to  the  air  and.  the  light.  The  apparatus  for  test- 


18  PHENOMENA  OF  PLANT-LIFE. 

ing  its  growing  force  consisted  of  a  frame,  or  bed,  of  seven 
inch  boards,  one  foot  long.  These  were  arranged  in  a  radial 
manner,  like  the  spokes  of  the  lower  half  of  a  wheel,  their 
inner  edges  being  turned  toward  the  central  axis.  These 
pieces  were  held  firmly  in  place  by  two  end-boards,  twelve 
inches  square,  to  the  lower  half  of  which  they  were  secured 
by  nails  and  iron  rods.  A  heini-ellipsoidal  cavity,  about  five 
inches  deep  in  the  centre  and  eight  inches  long,  was  cut  from 
the  inner  edges  of  the  seven  boards,  and  in  this  the  squash 
was  carefully  deposited,  the  stem  and  vine  being  carefully 
protected  by  blocks  of  wood  from  injury  by  compression. 
Over  the  squash  was  placed  a  semi-cylindrical  harness,  or 
basket  of  strap-iron,  firmly  rivetted  together.  The  meshes 
between  the  bands,  which  crossed  each  other  at  right-angles, 
were  about  one  inch  and  a  half  square.  The  harness  was 
twelve  inches  long  and  the  same  in  width,  so  that  when  placed 
over  the  squash,  it  just  filled  the  space  between  the  end- 
boards.  Upon  the  top  of  the  harness,  and  parallel  with  the 
axis  of  the  cylinder  and  the  squash,  was  fastened  a  bar  of 
iron  with  a  knife-edge  to  serve  as  the  fulcrum  of  a  lever  to 
support  the  weights  by  which  the  expansive  force  was  to  be 
measured.  At  first,  an  iron  bar,  one  inch  square,  was  used 
for  a  lever,  then  a  larger  bar  of  steel,  then  a  lever  of  chest- 
nut plank,  then  one  of  seasoned  white  oak  plank,  and,  finally, 
one  of  chestnut,  five  by  six  inches  square,  and  nine  feet  long ; 
but  even  this  required  to  be  strengthened  by  a  plate  of  iron 
four  inches  wide  by  half  an  inch  thick  and  five  feet  in  length. 
The  fulcrum  for  the  lever  was  also  renewed  from  time  to  time 
as  the  weight  was  increased. 

The  following  'table  shows  the  weight  of  iron  lifted  by  the 
squash  in  the  course  of  its  development : — 

August  21,  .         .         .         .         .  .         60  pounds. 

"  22,  ...      >.  69 

"  23,  .         .         .  91        " 

44  24,  .         .         .         .         .  .162 

"  25,  .         .         ...  .       225 

"  26,  .         .         .      •   „         .,  .       277 

"  27, '  356 

"  31,  500 


PHENOMENA  OF  PLANT-LIFE.  19 


September 

11,         
13,         

1,100  pounds. 
1  200 

« 

14,         

1,300 

tt 

15,         

1,400       " 

tt 

27,         

1,700       " 

tt 

30,         

2,015     ^ 

October 

3,     •   

2,115   //^ 

" 

12,         

2,500   -  " 

tt 

18,         .         .         .         .         . 

3,120    W> 

tt 

24,         

4,120     •% 

tt 

31, 

5,000       "'^ 

The 'last  weight  was  not  clearly  raised,  though  it  was  car- 
ried ten  clays,  on  account  of  tllfe  failure  of  the  harness  irons, 
which  bent  at  the  corners  under  the  enormous  pressure  of 
two  and  a  half  tons,  and  consequently  broke  through  the 
rind  of  the  squash.  It  was  not  feasible  to  remove  the  har- 
ness and  substitute  for  it  a  stouter  one,  on  account  of  its 
being  imbedded  in  the  substance  of  the  squash,  which  grew 
up  through  the  meshes  of  the  harness,  forming  protuberances 
an  inch  and  a  half  high  and  overlying  the  iron  bands.  When, 
on  the  seventh  of  November,  the  harness  was  removed  in 
order  to  take  a  plaster  cast  of  the  squash,  it  was  necessary 
to  cut  the  straps  with  a  cold-chisel,  sometimes  into  several 
pieces,  and  draw  them  out  endways. 

The  growing  squash  adapted  itself  to  whatever  space  it 
could  find  as  readily  as  if  it  had  been  a  mass  of  caoutchouc ; 
nor  did  it  ever  show  the  slightest  tendency  to  crack,  except 
in  the  epidermis.  This  would  often  open  in  minute  seams, 
from  which  a  turbid  mucilaginous  fluid  exuded.  In  the 
morning  drops  of  this  would  frequently  bedew  the  protuber- 
ances like  drops  of  perspiration.  In  the  sunshine  these  dried 
up  and  fell  off  as  minute  globules,  resembling  gum  Arabic. 

The  lifting  power  was  greatest  after  midnight,  when  the 
growth  of  the  vine  and  the  exhalation  from  the  foliage  was 
least. 

The  material  out  of  which  the  squash  was  formed  was 
elaborated  in  the  leaves  during  the  day-time,  and  transferred 
through  the  vine  to  the  stem.  Through  this  it  was  imbibed 
by  the  living,  growing  cells  of  the  squash,  which  were  con- 


20  PHENOMENA  OF  PLANT-LIFE. 

stantly  multiplying  by  subdivision  until  their  number  was 
many  billions,  notwithstanding  the  enormous  pressure  under 
which  they  were  forced  to  develop.  This  growth  was  possi- 
ble only  because  life  is  a  molecular  force  and  exerted  its 
almost  irresistible  power  over  an  immense  surface  of  cell 
membrane. 

Scarcely  less  astonishing  than  the  mechanical  force  exhib- 
ited was  the  ability  of  the  tissues  of  the  squash  to  resist 
chemical  changes  and  the  attacks  of  mould,  when  the  rind 
was  injured  by  bruises  or  cuts.  Whenever  fresh-growing 
cells  were  exposed  to  the  action  of  the  air,  they  immediately 
began  to  form  a  regular  periderm  of  cork,  precisely  similar 
in  appearance  and  structure  to  that  produced  upon  the  cork- 
oak,  the  elm,  and  other  trees.* 

The  form  of  the  squash  can  hardly  be  described,  but  may 
be  seen  in  the  drawings  which  show  the  upper  and  under 
sides.  The  weight  was  forty-seven  pounds  and  a  quarter, 
and  when  opened  the  rind  was  found  to  be  about  three  inches 
thick  and  unusually  hard  and  compact.  The  internal  cavity 
corresponded  in  general  form  to  the  exterior,  but  was  very 
small,  and  nearly  filled  with  fibrous  tissue  and  plump  and 
apparently  perfect  seeds  in  about  the  normal  number.  A 
squash  of  the  same  variety,  grown  in  the  field  by  Messrs. 
Russell  Brothers,  in  North  Hadley,  weighed  one  hundred  and 
twenty-three  pounds.  Its  form  was  ovoid,  but  flattened  as  if 
by  its  own  weight,  and  the  cavity  within  had  a*  capacity  of 
about  sixteen  quarts. 

Two  vines  having  been  started  together  in  our  experimen- 
tal bed,  it  was  decided  to  apply  a  mercurial  gauge  (such  as 
will  be  described  in  another  place)  to  the  neck  of  one  cut  off 
at  the  ground,  when  the  vine  was  about  eight  weeks  old  and 
had  a  length  of  twelve  feet.  The  result  was  quite  surpris- 
ing, greatly  surpassing  anything  heretofore  recorded,  so  far 
as  we  are  aware,  concerning  the  pressure  exerted  by  the  sap 
of  an  herbaceous  plant,  the  maximum  force  with  which  the 
root  of  the  squash  exuded  the  water  absorbed  by  it  being 
equal  to  a  column  of  water  48.51  feet  in  height.  The  gauge 
was  applied  about  noon,  August  27th.  At  2  p.  M.,  August 
28th,  the  temperature  of  the  pit  being  86°  Fahrenheit,  the 
pressure  on  the  gauge  equalled  31.70  feet  of  water. 


PHENOMENA  OF  PLANT-LIFE.  21 

At    4,  P.  M.,  Aug.  28,  it  was  29.47  feet,  Temp.  75°  Fahr. 

"     9,     "         "       28,      k<  25.78     "  "       63°  " 

"     7,  A.M.,     "       29,      "  32.30     "  "       63°  « 

"     2,  P.  M.,     "       29,      "  42.59     "  "       85° 

«     9,     "         "       29,       "  48.51     "  "       65°  " 

"    8,  A.M.,     "      30,      "  39.33     "  <k       70°'  " 

"  12,  M.           "      30,      "  35.25     "  "       84°  " 

"     7,  A.M.,     "      31,      "  27.88     "  "       67°  " 

"    8,     "     Sept.      1,      "  00.00     "  4t       00°  " 
[For  illustrations  relating  to  the  squash,  see  figures  1-16.] 

Gauges  were  also  attached  to  the  stumps  of  large  plants  of 
Indian  corn,  tobacco,  and  the  dahlia.  The  results  were  not 
specially  different  from  what  has  been  previously  observed  by 
Hofrneister  and  others.  The  flow  continued  but  a  very  few 
days,  and  the  pressure  varied  from  eight  to  twenty-five  feet 
of  water.  The  pressure  in  all  these  cases  seems  to  be  caused 
by  the  activity  of  the  absorbent  tissues  of  the  root ;  and  its 
cessation  results,  doubtless,  from  the  stagnation  of  the  sap  in 
the  gorged  cells  and  vessels,  and  the  consequent  decay  of  the 
root-hairs  and  fibres. 

The  frequent  displacement  of  flagging-stones,  and  the  dam- 
age often  done  to  brick  and  concrete  pavements  and  stone 
walls  by  the  roots  of  shade  trees,  considered  in  connection 
with  the  wonderful  expansive  power  exhibited  by  the  squash 
in  harness,  made  it  evident  that  growing  roots  of  firm  wood 
must  be  capable  of  exerting,  under  suitable  conditions,  a 
tremendous  mechanical  force.  Upon  searching  the  fields  for 
examples  of  trees  standing  upon  naked  rocks,  or  ridges 
covered  with  only  a  shallow  soil,  many  interesting  specimens 
were  readily  discovered  to  demonstrate  this  fact. 

In  South  Hadley,  Mass.,  a  sugar  maple  was  found  which 
had  gr<  wn  upon  a  horizontal  bed  of  red  sandstone.  The  tree 
stood  upon  the  naked  rock,  over  which  its  roots  extended  a 
few  feet  in  three  directions  into  the  soil.  One  root  had 
pushed  its  way  under  a  slab  of  rock  which  measured  more 
than  twenty-four  cubic  feet,  and  must  have  weighed  about 
two  tons.  In  the  course  of  twenty  years  or  more,  this  root 
had  developed  to  such  a  size  as  to  raise  the  slab  entirely  from 
the  bed-rock  and  from  the  earth,  and  so  that  it  rested  wholly 


22  PHENOMENA  OF  PLANT-LIFE. 

upon  the  wood.  Upon  examining  the  tree,  it  was  evident 
that  as  it  stood  upon  the  horizontal  roots  which  rested  on 
solid  rock  and  had  a  diameter  of  nearly  a  foot ;  and  as  they 
had  grown  by  the  deposition  of  an  annual  layer  of  wood  en- 
tirely around  them  ;  and  as  the  heart,  now  several  inches  from 
the  rock,  must  once  have  rested  on  it ;  and  as  the  rock  could 
not  have  been  depressed, — therefore,  the  tree  had  been  lifted 
every  year  by  the  growing  wood  of  the  outside  layer. 

Another  tree  of  paper  birch  having  been  found  growing  in 
a  similar  manner,  one  of  the  horizontal  roots  was  sawed 
through,  and  the  centre  of  the  heart  was  seen  to  have  been 
elevated  seven  inches  since  the  tree  was  a  seedling. 

Mr.  William  F.  Flint,  a  student  in  the  Agricultural  College 
of  New  Hampshire,  has  rendered  valuable  assistance  in  find- 
ing specimens  of  trees  which  illustrate  this  principle  in  an 
admirable  manner.  Drawings  of  two  such  examples  selected 
from  a  large  number  furnished  by  him  are  appended  to  this 
paper.  (Figs.  18,  19.) 

Now  it  is  clearly  demonstrated  that  the  power  of  vegetable 
growth  can  lift  a  tree,  and  that  it  must  do  so,  whenever  the 
bed  of  the  roots  cannot  be  depressed.  It  is  evident  also  that 
old  trees  on  a  clay  hard-pan  or  any  other  unyielding  subsoil 
must  be  thrown  up  by  the  process  of  growth.  Every  person 
is  familiar  with  the  fact  that  large  trees  usually  have  the  ap- 
pearance of  having  been  thus  raised,  and  their  roots  are  often 
bare  for  a  considerable  distance  around  the  trunk. 

This  lifting  of  the  tree  from  its  bed  would  seem  to  be  ad- 
vantageous to  it  by  tightening  the  roots  so  as  to  hold  it  firmly 
in  place,  notwithstanding  the  possible  elongation  of  their 
woody  fibre  by  the  tremendous  strains  to  which  they  are  sub- 
jected during  violent  storms.  This  method  of  securing  the 
tree  in  place  would  be  still  further  improved  by  the  constant 
enlargement  of  the  roots  by  the  annual  deposition  of  a  layer 
of  wood,  and  the  consequent  filling  of  any  spaces  formed  in 
the  soil  by  the  movements  of  the  roots,  caused  by  the  sway- 
ing of  the  tree  in  the  wind. 

This  slight  annual  elevation  of  trees  by  the  increase  in  di- 
ameter of  their  horizontal  roots  furnishes  an  explanation  for 
the  differences  of  opinion  in  regard  to  the  question  whether  a 
given  point  on  the  trunk  of  a  tree  is  raised  in  the  process  of 


PHENOMENA  OF  PLANT-LIFE.  23 

its  growth.  While  it  has  been  demonstrated  by  Prof.  Asa  Gray 
that  two  points  in  a  vertical  line  on  the  trunk  of  a  tree  will  not 
separate  as  it  enlarges,  it  seems  equally  clear  that  both  of 
them  may  be  quite  perceptibly  elevated  in  the  course  of  time. 

It  has  been  stated  on  good  authority  that,  at  Walton  Hall, 
in  England,  a  mill-stone  was  to  be  seen,  in  1863,  in  the  cen- 
tre of  which  was  growing  a  filbert  tree,  which  had  completely 
filled  the  hole  in  the  stone,  and  actually  raised  it  from  the 
ground.  The  tree  was  said  to  have  been  produced  from  a  nut, 
which  was  known  to  have  germinated  in  1812.  The  above 
story  has  been  declared  false,  because,  as  asserted,  the  tree 
could  not  have  exerted  any  lifting  power  upon  the  stone.  It 
is,  however /not  difficult  to  see  that  it  may  be  true,  and  is  even 
probable. 

Yet  it  should  be  remembered  that  the  amount  of  elevation, 
in  any  case  where  it  occurs  from  the  increase  in  the  size  of 
horizontal  roots,  must  depend  upon  the  firmness  of  the  mate- 
rial on  which  they  rest,  and  can  never  exceed  one-half  the 
diameter  of  the  largest  roots.  When,  therefore,  a  writer,  as 
has  happened,  asserts  that,  during  a  visit  to  Washington  Irv- 
ing at  Sunny  side,  he  carved  his  name  upon  the  bark  of  a  tree 
beneath  which  he  was  sitting  in  conversation  with  the  illustri- 
ous author,  and  that  many  years  after  he  went  to  the  place, 
and  with  much  difficulty  discovered  the  identical  inscription, 
high  up  among  the  branches,  far  above  his  reach,  it  is  alto- 
gether probable  that  his  feelings  were  too  many  and  too  ex- 
alted for  the  ordinary  use  of  his  intellectual  faculties. 

Since  the  publication  of  the  paper  on  the  "  Circulation  of 
the  Sap  in  Plants."  in  the  last  volume  of  the  Agriculture  of 
Massachusetts,  a  course  of  lectures  on  the  "Physiology  of 
the  Circulation  in  Plants,  in  the  Lower  Animals,  and  in  Man," 
by  Dr.  J.  Bell  Pettigrew,  has  been  published  by  Macmillan  & 
Co.,  of  London.  The  hypotheses  adopted  by  this  author  are 
quite  extraordinary,  and  .evidently  announced  without  the 
slightest  attempt  at  demonstration,  although  he  has  invented 
a  new  method  of  accounting  for  the  phenomena  of  the  motions 
of  the  sap.  Thus  he  says,  "In  trees  the  sap  flows  steadily 
upward  in  spring,  and  steadily  downward  in  autumn."  Also, 
"Much  more  sap  is  taken  up  than  is  given  off  in  spring,  in 
order  to  administer  to  the  growth  of  the  plant.  In  autumn, 


24  PHENOMENA  OF  PLANT-LIFE. 

when  the  period  of  growth  is  over,  this  process  is  reversed, 
more  sap  being  given  off  by  the  roots  than  is  taken  up  by 
them."  Now,  this  is  pure  assumption,  there  being  no  proof 
that  the  sap  of  trees  escapes  from  the  roots  in  autumn/  In 
fact,  it  appears  that  the  wood  of  trees  contains  as  much  sap  in 
winter,  when  at  rest,  as  in  the  period  of  most  active  growth. 

Again,  Dr.  Pettigrew  remarks  :  "  It  is  difficult  to  understand 
how  excess  of  moisture  in  the  ground  can  be  drawn  up  into 
the  plant  and  exhaled  by  the  leaves  at  one  period,  and  excess 
of  moisture  in  the  atmosphere  seized  by  the  plant,  and  dis- 
charged by  the  roots  at  another.  The  explanation,  however, 
is  obvious,  if  we  call  to  our  aid  the  forces  of  endosmose  and 
exosmose.  The  tree  is  always  full  of  tenacious;  dense  saps, 
and  it  is  a  matter  of  indifference  whether  a  thinner  watery  fluid 
be  presented  to  its  roots  or  its  leaves ;  if  the  thinner  fluid  be 
presented  to  its  roots,  then  the  endosmotic  or  principal  cur- 
rent sets  rapidly  in  an  upward  direction  ;  if,  on  the  other  hand, 
the  thinner  fluid  be  presented  to  its  leaves,  the  endosmotic  or 
principal  current  sets  rapidly  in  a  downward  direction." 

This  explanation  is  not  only  false,  but  superfluous,  since  no 
such  circulation  can  be  shown  to  exist,  but  is  an  excellent  sam- 
ple of  the  common  mode  of  dealing  with  this  obscure  subject. 
Instead  of  seeking  to  discover  the  exact  facts  concerning  the 
composition  and  movements  of  the  sap  -  in  all  parts  of  the 
plant,  a  display  of  book-knowledge  is  made  by  quoting  from 
numerous  writers  of  some  repute,  such  statements  as  seem  to 
corroborate  the  hypotheses  of  the  author.  The  assumed  phe- 
nomena of  the  circulation  are  then  accounted  for  in  an  appar- 
ently scientific  manner  by  ingenious  allusions  to  osmose,  cap- 
illarity, and  other  physical  forces,  the  surprising  possibilities 
of  which  are  duly  recounted. 

Dr.  Pettigrew  further  observes,  that  "Herbert  Spencer  be- 
lieves that  the  upward  and  downward  circulation  of  crude  and 
elaborated  saps  takes  place  in  a  single  system  of  vessels  or 
vertical  tubes."  To  explain  this  extraordinary  assumption, 
Mr.  Spencer  states  that  "the  vessels  of  the  branches  termi- 
nate in  club-shaped  expansions  in  the  leaves,  which  expan- 
sions act  as  absorbent  organs,  and  may  be  compared  to  the 
spongioles  of  the  root.  If,  therefore,  the  spongioles  of  the 
root  send  up  the  crude  sap,  it  is  not  difficult  to  understand 


PHENOMENA  OF  PLANT-LIFE.  25 

how  these  spongioles  of  the  leaf  send  down  the  elaborated  sap, 
one  channel  sufficing  for  the  transit  of  both."  This  hypothesis 
concerning  the  circulation  of  sap  is  accepted  only  by  its  inventor, 
and  is  directly  opposed  to  most  of  the  facts  of  plant-growth. 

Finally,  Dr.  Pettigrew  has  conceived  a  system  of  syphons 
by  the  aid  of  which  he  is  able  to  account  to  his  entire  satis- 
faction for  all  he  knows  concerning  the  circulation  of  sap. 
He  says  :  "The  vessels  which  convey  the  sap,  as  is  well  known, 
are  arranged  in  more  or  less  parallel  vertical  lines.  If  the 
vessels  are  united  to  each  other  by  a  capillary  plexus,  or,  what 
is  equivalent  thereto,  in  the  leaves  and  roots,  they  are  at  once, 
as  has  been  shown,  converted  into  syphon-tubes,  one  set 
bendinir  upon  itself  in  the  leaves,  the  other  set  bending  upon 
itself  in  the  roots.  As,  however,  a  certain  portion  of  the 
syphon-tubes,  which  bend  upon  themselves  in  the  roots, 
are  porous  and  virtually  open  towards  the  leaves  ;  while  a 
certain  portion  of  the  syphon-tubes,  which  bend  upon  them- 
selves in  the  leaves,  are  porous  and  virtually  open  toward 
the  roots, — it  follows  that  the  contents  of  the  syphon-tubes 
may  be  made  to  move  by  an  increase  or  decrease  of  moisture, 
heat,  etc.,  either  from  above  or  from  below.  In  spring,  the 
vessels  may  be  said  to  consist  of  one  set,  because  at  this  period 
the  leaves  and  the  connecting  plexuses  which  they  contain 
do  not  exist.  All  the  vessels  at  this  period  may,  therefore, 
be  regarded  as  carrying  sap  in  an  upward  direction  to  form 
shoots,  buds  and  leaves,  part  of  the  sap  escaping  laterally, 
because  of  the  porosity  of  the  vessels.  In  summer,  when  the 
leaves  are  fully  formed,  the  connecting  links  are  supplied  by 
the  capillary  vascular  expansions  formed  in  them, — the  tubes 
are  in  fact  converted  into  syphons.  As  both  extremities  of 
the  syphons  are  full  of  sap  in  spring  and  early  summer,  an 
upward  and  a  downward  current  is  immediately  established. 
When  the  downward  current  has  nourished  the  plant  and 
stored  up  its  starched  granules  for  the  ensuing  spring,  the 
leaves  fall,  the  syphon  structure  and  action  is  interrupted,  and 
all  the  tubes  (they  are  a  second  time  single  tubes)  convey  mois- 
ture from  above  downward,  as  happens  in  autumn.  As  the 
vascular  expansions  or  networks  are  found  also  in  the  stems 
of  plants,  it  may  be  taken  for  granted  that  certain  of  the  tubes 
are  united  in  spring,  the  upward  rush  of  sap  being  followed 


26  PHENOMENA  OF  PLANT-LIFE. 

by  a  slight  downward  current,  as  happens  in  endosmose  and 
exosmose.  As,  moreover,  the  spongioles  of  the  roots  and 
the  leaves  are  analogous  structures,  and  certain  tubes  are  united 
in  the  roots,  the  downward  current  in  autumn  is  accompanied 
by  a  slight  upward  current.  This  accounts  for  the  fact  that 
at  all  periods  of  the  year,  the  upward,  downward  and  trans- 
verse currents  exist ;  the  upward  and  downward  currents  be- 
ing most  vigorous  in  spring  and  autumn,  and  scarcely  percep- 
tible in  winter.  Furthermore,  as  some  of  the  vascular  expan- 
sions in  the  leaves  are  free  to  absorb  moisture,  etc.,  in  the 
same  way  that  the  spongioles  are,  it  follows  that  the  general 
circulation  may  receive  an  impulse  from  the  leaves  or  from  the 
roots,  or  both  together,  the  circulation  going  on  in  a  continu- 
ous current  in  certain  vessels." 

This  original  effort  of  the  learned  lecturer  on  physiology, 
at  Surgeons'  Hall,  in  Edinburgh,  published  in  1874,  to  explain 
some  of  the  most  difficult  problems  of  vegetable  life  by  a 
mere  hypothesis,  which  assumes  that  sap  flows  in  the  vessels ; 
that  there  are  spongioles  in  the  leaves  which  absorb  water ; 
that  the  sap  descends  to  the  roots  and  escapes  from  them  in 
autumn ;  and  that  an  imaginary  system  of  syphons  does  all 
these  wonderful  things,  which  have  not  been  proved  to  occur 
at  all,  and  which  well-informed  physiologists  are  almost 
unanimous  in  denying,  reminds  us  of  the  adage  that  "a 
prophet  is  not  without  honor  save  in  his  own  country."  This 
is  not  the  method  of  the  Baconian  philosophy. 

In  the  observations  which  follow,  we  hope  to  add  some  new- 
facts  to  the  knowledge  of  the  world  concerning  the  phenom- 
ena of  plant  growth ;  but  are  painfully  conscious  of  the  need 
of  much  more  investigation  before  a  complete  and  correct 
theory  of  the  circulation  of  sap  can  be  stated.  Exceptions 
have  been  taken  to  the  use  of  the  expression  "  circulation  of 
sap " ;  but  since  there  is  an  evident  distinction  between  the 
crude  and  elaborated  saps,  both  in  their  composition  and 
their  location  in  the  plant,  at  least  in  the  higher  forms  of 
vegetation,  and  since  the  circulation  of  blood  is  accepted  as 
a  proper  term  even  when  applied  to  animals  without  a  heart, 
we  prefer  to  retain  it  in  our  vocabulary. 

In  regard  to  the  causes  which  induce  the  absorption  of 
water  and  soluble  substances  by  the  roots  of  living  plants,  it 


PHENOMENA  OF  PLANT-LIFE.  27 

seems  unfortunate  that  so  much  has  been  claimed  for  osmose 
in  this  connection.  Boussingault  has  recently  shown  that 
roots  containing  sugar  do  not  exude  it  when  growing  in 
water,  while  leaves  and  fruits,  when  immersed  in  this  fluid, 
readily  absorb  it  by  an  osmotic  process  and  part  with  their 
sugar:  If  the  enormous  absorption  of  water  by  the  roots  of 
birch  trees,  in  spring,  were  accompanied  by  any  correspond- 
ing exudation,  it  would  appear  easy  to  find  it ;  but  no  one 
has  yet  detected  it.  It  is  not  possible  to  account  for  the  fact 
that  when  sap  is  rising  most  rapidly,  none  will  flow  from  a 
wound  in  the  bark,  even  when  it  will  run  a  stream  from  the 
outer  layer  of  wood,  if  the  circulation  in  the  trunk  is  caused 
by  osmose.  There  is  fresh  cellular  tissue  in  the  liber,  and 
some  soluble  material,  but  the  bark  remains  comparatively 
dry  till  growth  begins.  After  the  cambium  has  become 
abundant,  why  should  not  all  the  crude  sap  press  toward  it 
and  draw  the  elaborated  material  directly  into  the  wood, 
instead  of  pushing  its  way  against  the  force  of  gravity  to 
the  leaves,  if  osmose  is  so  powerful  an  agent  in  the  circula- 
tion? If  this  tendency  to  press  into  the  bark  were  to  exist, 
there  would  be  a  much  greater  flow  from  places  that  are 
girdled  than  is  now  observed ;  and  probably  the  bark  itself 
would  be  ruptured  by  the  pressure  exerted,  which  would 
often  be  equal  to  more  than  thirty  pounds  to  the  square 
inch. 

One  of  the  most  surprising  facts  to  be  noticed  in  examin- 
ing the  wood  of  any  tree  with  well-developed  foliage,  is  the 
entire  absence  of  anything  like  free  or  fluid  water.  A 
freshly-cut  surface  of  the  sap-wood  is  not  even  moist  to  the 
touch  ;  and  if  a  tube  be  inserted  into  the  trunk  of  such  a 
tree,  it  will  frequently  absorb  water  with  great  avidity.  On 
the  sixth  of  June  last,  a  half-inch  tube  six  feet  in  length  was 
attached  to  a  stopcock  inserted  into  the  trunk  of  an  elm  and 
the  tube  filled  with  water.  The  absorption  was  so  rapid  that 
the  fluid  disappeared  in  thirty  minutes,  and  this  was  repeated 
several  times  the  same  day.  Similar  observations  were  made 
upon  white  oak,  chestnut  and  buttonwood  trees. 

Now  the  absorption  was  not  osmotic,  since  the  rapidity  of 
it  was  too  great  and  there  was  no  outward  flow,  but  appa- 
rently the  result  of  imbibition,  or  the  affinity  of  the  cellulose 


28  PHENOMENA  OF  PLANT-LIFE. 

of  the  woody  fibre  for  water.  Is  not  this,  then,  the  proper 
name  for  the  force  which  carries  up  the  crude  sap  ? 

The  wood  of  growing  trees  when  cut  from  near  the  sur- 
face, though  apparently  dry,  contains  nearly  fifty  per  cent, 
of  water;  and  in  the  young  twigs,  with  a  living  pith,  the 
proportion  is  even  greater.  A  number  of  analyses  have  been 
made  of  specimens  collected  at  different  seasons  during  the 
past  year,  of  which  a  tabular  statement  is  appended. 

There  is  good  reason  to  believe  that  the  sap  in  ordinary 
trees  begins  to  move  first  in  the  buds,  and  that  the  first  sup- 
ply of  water  exhaled  in  the  spring  is  derived  from  the  sap- 
wood.  Branches  of  aspen  and  red  maple,  two  feet  in  length, 
were  cut  on  the  twenty-sixth  of  March  and  placed  in  a  warm 
room  in  an  empty  vase.  The  flower-buds  developed  without 
any  other  water  than  what  they  could  abstract  from  the 
wood,  so  that  on  the  fifth  day  the  staminate  catkins  of  the 
aspen  were  four  inches  long,  and  the  pollen  well  developed. 
It  is  by  no  means  uncommon  to  see  large  branches,  which 
have  been  removed  from  apple  trees  early  in  the  spring,  covered 
with  blossoms  in  a  similar  way  while  lying  on  the  ground. 

It  is  a  well-established  fact  that  the  roots  of  most  woody 
plants  have  not  power  at  any  season  to  force  water  to  any 
considerable  height  when  separated  from  their  stems.  Upon 
this  point  a  large  number  of  observations  have  been  made, 
which  will  be  described  in  another  place. 

The  roots  of  all  plants  growing  on  ordinary  soil  develop 
most  freely  and  absorb  most  abundantly  when  the  earth  is  well 
drained  and  aerated.  Thus  we  find  that  the  crude  sap  im- 
bibed by  the  root-hairs  from  the  surface  of  the  particles  of  the 
soil  seems  to  be  taken  up  in  a  dry  state,  that  is,  it  appears  to 
be  absorbed  molecule  by  molecule,  no  fluid  water  being  visible, 
and  carried  in  this  form  through  all  the  cellulose  membranes 
between  the  earth  and  the  leaf,  by  which  it  is  to  be  digested 
or  exhaled.  We  do  not  say  this  is  literally  true,  but  it  ac- 
cords very  nearly  with  what  is  constantly  to  be  seen  in  some 
species  of  plants.  The  circulation  of  the  sap  in  a  poplar  tree 
is  very  dry  compared  with  that  of  the  blood  of  any  animal. 
Not  a  drop  of  moisture  will  ever  flow  from  the  wood  of  an 
aspen,  so  far  as  we  have  observed.  Nevertheless,  it  grows 
very  freely  and  starts  very  early  in  the  season. 


PHENOMENA  OF  PLANT-LIFE.  29 

That  living  cellulose  has  a  peculiar  and  very  powerful 
affinity  for  water  is  evident  from  the  experiments  of  De  Vries, 
who  discovered  that  when  a  shoot  of  an  herbaceous  plant  with 
large  leaves  is  cut,  and  the  fresh  surface  allowed  to  come  for 
a  short  time  into  contact  with  the  air,  it  loses  much  of  its 
absorbing  power  and  the  leaves  wilt.  If,  however,  the 
section  be  made  under  water,  so  that  the  living  tissue  is 
not  exposed  to  the  air,  its  power  of  imbibition  remains 
unimpaired,  and  the  leaves  do  not  wilt. 

It  appears,  therefore,  that  much  of  the  crude  sap  passes 
through  the  membranes  of  the  sap-wood  or  woo^y  fibre  or 
cellular  tissue  of  plants  in  an  apparently  solid  form,  combined 
with  the  cellulose,  just  as  the  water  in  dry  slacked  lime,  or  a 
plaster  cast  is  in  a  solid  form.  In  all  these  cases  it  may  be 
obtained  as  a  liquid  by  distillation  at  a  temperature  of  212° 
Fahrenheit.  The  cause  of  the  motion  seems  to  be  the  removal 
of  the  water  from  the  tissue  at  some  point  by  exhalation,  by 
chemical  combination  or  by  assimilation.  Whenever  any 
portion  of  the  living  cellulose  has  an  insufficient  amount  of 
water  to  saturate  its  affinity,  it  imbibes  an  additional  quantity 
and  this  process  is  continued  from  cell  to  cell  downward,  or 
backward  to  the  roots  and  the  earth. 

The  conducting  power  of  the  cellulose  of  sap-wood  is  very 
remarkable,  as  is  seen  in  the  fact  that  whenever  a  limb  of  an 
apple  or  peach  tree  breaks  down  under  its  burden  of  fruit,  it 
very  rarely  wilts  or  fails  to  ripen  its  crop.  Those  who  have 
compared  the  area  of  a  section  of  the  trunk  of  a  large  tree 
with  the  area  of  a  section  of  its  branches  at  any  point  above, 
must  have  noticed  that  the  relative  amount  of  sap-wood 
rapidly  increases  as  we  ascend  toward  the  top,  the  young 
twigs  and  branches  containing  no  other  wood. 

An  elm  in  Amherst,  famous  for  the  beautiful  symmetry  of 
its  form  and  known  as  the  Ay  res  elm,  was  carefully  measured 
by  Prof.  Graves  and  the  senior  class.  The  area  of  the  sec- 
tions of  the  branches  twenty  feet  from  the  ground  was  more 
than  twice  as  great  as  the  area  of  a  section  of  the  trunk  four 
feet  from  the  earth,  and  the  proportion  of  sap-wood  was  of 
course  much  greater. 

An  interesting  experiment  was  undertaken  in  the  Durfee 
Plant-house  to  determine  how  small  a  proportion  of  sap-wood 


30  PHENOMENA  OF  PLANT-LIFE. 

could  conduct  the  necessary  supply  of  sap  to  the  foliage  of  a 
growing  tree,  and  also  whether  the  bark  alone  could  furnish 
the  requisite  water  to  prevent  the  leaves  from  wilting.  A 
specimen  of  Hibiscus  splendens,  standing  in  the  ground  and 
having  three  stems  from  the  same  root,  was  selected  for  trial. 
The  shrub  was  growing  rapidly,  and  was  prepared  for  the 
experiment  as  follows  :  Two  of  the  stems  were  tied  firmly  to 
stakes,  and  the  third  left  undisturbed.  The  first  specimen 
had  all  the  bark  removed  from  one  inch  of  the  stem,  and  then 
the  wood  was  cut  away  till  there  remained  only  a  small  piece 
of  the  outride  layer  of  sap-wood,  which  was  one  inch  long  and 
seven-sixteenths  of  an  inch  in  circumference.  This  exposed 
surface  was  immediartely  covered  with  grafting-wax,  to  protect 
the  tissues  from  the  action  of  the  air.  The  amount  of  stem 
remaining  was  just  one  eighty-fourth  of  the  original,  which 
was  about  four  inches  around.  The  healthy  leaf- surface  was 
fully  twenty-five  hundred  square  inches,  from  both  sides  of 
which  exhalation  went  on  to  some  extent,  making  five  thou- 
sand square  inches  of  exhaling  surface.  The  result  was,  that 
the  foliage  remained  perfectly  fresh  and  vigorous  for  ten  days, 
until,  on  the  tenth  of  November,  the  specimen  was  cut  for 
the  museum.  (Figs.  20,  21.) 

The  other  stem  was  used  to  determine  whether  by  osmose, 
or  in  any  other  way,  the  crude  sap  could  ascend  in  the  bark 
and  supply  the  leaves  with  water.  All  the  wood  and  one- 
third  of  the  bark  were  removed  from  a  portion  one-half  inch 
in  length,  the  exposed  tissues  protected  by  wax,  and  the 
branches  so  pruned  as  to  leave  only  . five  hundred  square 
inches  of  leaf-surface.  The  foliage  all  drooped  in  a  single 
hour  and  never  recovered.  This  experiment  showed  that  the 
bark  was  altogether  incompetent  to  furnish  the  requisite 
supply  of  crude  sap  to  the  parts  above  it,  although  it  was 
thick  and  succulent,  and  much  greater  in  quantity,  when  com- 
pared with  the  exhaling  surface,  than  the  piece  of  sap-wood 
which  showed  such  marvellous  conducting  power.  If  osmose 
were  the  cause  of  the  ascent  of  sap,  it  would  seem  that  the 
abundant  parenchyma  of  the  bark,  intimately  united  as  it  is 
with  the  wood  by  the  medullary  rays,  must  freely  transmit 
the  amount  required  in  this  case.  But  the  leaves  wilted  and 
perished  as  quickly  as  if  the  entire  stem  had  been  severed. 


PHENOMENA  OF  PLANT-LIFE.  31 

Having  thus  demonstrated  that  crude  sap  ascends  chiefly 
in  the  sap-wood  of  exogenous  trees,  let  us  now  consider  a 
few  facts  which  appear  to  prove  that  there  is  a  counter-move- 
ment of  elaborated  sap  which  is  for  the  most  part  confined  to 
the  bark. 

It  is  well  known  that  if  a  narrow  ring  of  bark  be  removed 
from  the  trunk  of  a  tree  between  the  leaves  and  the  roots, 
then  the  deposition  of  wood  ceases  below  the  girdled  place, 
though  above  it  the  growth  for  the  season  ensuing  will  be 
quite  normal.  This  proves  beyond  dispute  that  the  wood 
cannot  convey  that  portion  of  the  elaborated  sap  which  is 
essential  to  growth,  and  that  it  can  be  conducted  only  by  the 
tissues  of  the  bark,  or  the  imperfectly-developed  tissues  of 
the  cambium  between  it  and  the  perfectly-formed  wood. 
Nevertheless,  there  is  free  communication  in  a  transverse 
direction  for  the  crude  sap  and  for  some  of  the  elaborated 
substances  between  the  wood  and  the  bark,  probably  by 
means  of  the  medullary  rays  which  connect  the  two.  Thus 
only  can  we  account  for  the  fact  that  the  bark  below  a  girdled 
place  remains  alive  long  after  the  deposition  of  wood  ceases, 
and  also  for  the  circumstance  that  starch  and  sugar,  which 
must  originally  come  from  the  leaves,  are  found  either  accu- 
mulated in  the  cells  of  certain,  stems  and  roots,  or  existing  in 
the  sap  which  flows  or  is  expressed  from  their  tissues.  If  we 
shave  off,  little  by  little,  the  bark  of  a  maple  when  the  sap  is 
flowing  freely,  we  shall  observe  no  exudation  from  any  por- 
tion of  the  liber,  even,  but  as  soon  as  the  whole  of  this  is 
removed,  the  sap  issues  from  every  part  of  the  surface. 

Again ;  those  who  work  with  mill-logs  tell  us  that  in  the 
spring  the  bark  becomes  soft  and  loose,  precisely  as  if  the 
tree  were  standing,  at  least  in  the  case  of  some  species. 
Sometimes  logs  and  poles,  cut  for  fences,  will  sprout  and 
actually  produce  shoots  with  foliage,  the  sap  of  which  must 
be  derived  wholly  from  the  timber,  and  must,  therefore,  pass 
from  the  wood  to  the  bark. 

Mr.  Wm.  F.  Flint  has  sent  us  a  piece  of  a  red  maple  slab, 
which  he  found  on  moist  ground,  under  a  pile  of  wood,  and 
which  had  thrown  out  at  the  ends  and  sides  a  callous  a 
quarter  of  an  inch  thick,  precisely  like  an  ordinary  cutting  of 
a  grape  vine.  Here  we  have  an  instance  of  growth  without 


32  PHENOMENA  OF  PLANT-LIFE. 

either  roots,  buds,  or  leaves,  all  the  material  for  which  must 
have  been  derived  from  the  stick  itself.     (Fig.  22.) 

Similar  to  this  in  character  is  the  curious  circumstance,  not 
very  unfrequent,  of  old  potatoes  resolving  themselves  into  sev- 
eral smaller  ones,  within  the  skin  of  the  parent  tuber,  without 
any  external  appearance  of  vegetation.  This  is  reported  to 
have  occurred  in  a  vast  number  of  tubers,  in  a  quantity  of  po- 
tatoes on  board  a  vessel  in  the  Arctic  ocean,  where  the  low 
temperature  probably  exerted  some  influence  in  causing  this 
peculiar  mode  of  sprouting. 

An  excellent  demonstration  of  the  transverse  diffusion  of 
sap  was  obtained  in  some  experiments  performed  to  observe 
the  result  of  protecting  girdled  places  on  trees  from  the  effects 
of  exposure.  Healthy  young  trees,  or  large  branches,  of  elm, 
chestnut,  apple,  grape,  and  white  pine  were  drawn  through 
glass  tubes,  two  inches  in  diameter  and  two  feet  long,  upon 
either  end  of  which  were  fastened  short  pieces  of  rubber  hose. 
These  tubes  were  placed  over  girdled  spots,  from  which  the 
bark  was  removed  on  the  thirtieth  of  May  last,  and  the  rub- 
ber securely  fastened  with  iron  wire  to  the  tree.  From  all  of 
these  specimens  a  considerable  quantity  of  sap  escaped,  appar- 
ently in  the  form  of  vapor,  and  was  collected  in  the  tube. 
There  was  no  layer  of  wood  formed,  but  the  foliage  of  all  ex- 
cept the  pine  was  killed  before  autumn,  apparently  by  the 
fermentation  of  the  sap  and  its  re-absorption  into  the  wood. 
In  the  case  of  an  elm  root,  treated  in  a  similar  manner,  the 
bark  was  renewed,  probably  from  the  fact  that  the  cambium 
was  in  a  more  advanced  state  than  in  the  other  instances.  The 
root  was  dug  up  with  care,  twenty  feet  of  it  drawn  through 
the  tube,  and  then  covered  again  with  earth.  (Fig.  23.) 

With  the  view  of  determining  some  facts  concerning  the 
functions  of  the  bark  in  connection  with  the  circulation  of 
sap  and  the  growth  of  wood,  many  experiments  have  been  un- 
dertaken at  the  College  during  the  past  two  years,  and  some 
interesting  results  obtained. 

In  order  to  learn  whether  the  annual  layer  of  wood  upon 
trees  is  developed  from  the  outside  of  the  old  wood  or  from 
the  inside  of  the  bark,  the  following  plan,  suggested  by  the 
interesting  experiments  of  Duhamel  more  than  a  century  ago, 
was  tried.  Vigorous  young  trees  of  elm,  glaucous  willow, 


PHENOMENA  OF  PLANT-LIFE.  33 

and  chestnut  were  selected,  which  were  from  two  to  three 
inches  in  diameter.  On  the  thirtieth  of  May,  before  any  de- 
position of  recently  organized  tissue  was  visible,  but  when  the 
bark  was  easily  separated  from  the  wood,  a  horizontal  incision 
was  made  with  a  sharp  knife  around  each  stem,  and  immedi- 
ately above  this  four  vertical  incisions  on  the  four  quarters  of 
the  stem  about  three  inches  in  length.  The  four  strips  of 
bark  were  then  carefully  detached  from  the  wood  at  their  lower 
ends,  and  a  piece  of  tinned  copper,  one  inch  wide,  and' long 
enough  to  reach  around  the  wood  and  overlap,  was  adjusted 
to  the  trunk.  The  bark  was  then  replaced  and  covered  tightly 
with  cloth  which  had  been  dipped  in  melted  grafting-wax.  The 
trees  grew  through  the  season  as  usual,  and  after  the  fall  of  the 

o  o 

leaves  the  bandages  we  e  removed  and  the  results  observed 

In  all  cases  the  new  wood  was  found  to  have  been  deposited 
from  the  bark  and  outside  of  the  metallic  band.  Examina- 
tion under  the  microscope  showed  that  a  thin  layer  of  paren- 
chyma, corresponding  to  the  pith  of  the  first  year's  wood  and 
snch  as  probably  unites  all  the  layers  of  wood  in  exogenous 
steins,  was  formed  upon  the  metal,  and  outside  of  this  the 
fibro-vascular  tissue,  while  the  medullary  rays  were  as  numer- 
ous as  in  the  other  portions  of  the  layer  of  wood,  and  ex- 
tended directly  from  the  bark  to  the  metal  under  it,  whether 
examined  in  a.  transverse  or  a  longitudinal  section,  —  thus 
proving  that  the  material  did  not  flow  down  in  an  organized 
condition  from  above  the  band.  The  figures  appended  will 
render  the  entire  experiment  sufficiently  intelligible.  (Figs. 
24-27.) 

This  quite  satisfactory  result  demonstrates  that  the  elabo- 
rated material  formed  in  the  leaves  descends  altogether  outside 
of  the  wood,  and  that  the  inner  bark  is  the  most  highly  vital- 
ized part  of  the  trunk  of  a  tree  and  the  source  of  the  new 
layers  of  wood  and  bark  which  are  annually  produced. 

Much  information  has  also  been  obtained  in  regard  to  the 
effects  of  ringing  or  girdling  the  trunks  and  branches  of  trees 
by  the  removal  of  a  band  of  bark  only,  or  of  bark  and  sap- 
wood  from  the  entire  circumference. 

This  has  long  been  practised  in  new  countries  to  kill  the 
timber  which  the  settler  had  not  time  to  fell,  but  must  destroy 
to  obtain  grain  and  other  crops. 


34  PHENOMENA  OF  PLANT-LIFE. 

The  Chinese  are  said  to  produce  curious  dwarf  fruit-trees 
by  ringing  a  fruit-bearing  branch  and  placing  over  the  spot  a 
flower-pot  with  earth  in  which  roots  are  developed,  so  that  it 
may  then  be  detached  from  the  parent  tree  and  cultivated  in- 
dependently. The  Italians  propagate  the  jig-tree  in  a  similar 
manner,  and  this  process  may  be  m;ide  very  useful  in  securing 
the  certain  growth  of  a  sporting  branch  of  any  woody  plant, 
or  of  the  branches  of  species  with  spongy  or  pithy  wood 
which  will  not  root  from  cuttings.  It  is  a  well-known  fact 
that  the  ringing  of  a  branch  of  a  vine  or  tree  will  tend  to  in- 
crease the  size  of  the  fruit  the  following  season,  because  the 
branch  is  thereby  gorged  with  elaborated  material  for  which 
there  is  no  outlet,  and  some  persons  habitually  adopt  this 
mode  of  improving  their  fmit. 

In  the  town  of  Southborough,  Mass.,  is  an  apple  orchard 
of  healthy  trees,  from  twelve  to  sixteen  inches  in  diameter, 
which  were  all  girdled  by  the  owner,  Mr.  Trowbridge  Brig- 
ham,  in  the  spring  of  1870,  for  the  purpose  of  inducing  fruit- 
fulness.  The  desired  result  is  said  to  have  been  obtained, 
and  the  trees  seem  to  have  suffered  no  material  injury,  owing 
to  the  imperfect  manner  in  which  the  operation  was  performed. 
At  the  time  when  the  trees*  were  in  full  blossom,  a  narrow 
belt  of  bark,  usually  less  than  an  inch  in  width,  was  removed 
from  the  trunks,  about  two  feet  from  the  ground.  This  did 
not  peel  freely  in  all  cases,  and  there  were  many  crevices 
where  it  was  retained.  By  means  of  these  connecting  links, 
the  communication  between  the  leaves  and  the  root  was  im- 
perfectly preserved,  and  during  the  season  new  wood  and  bark 
were  developed  upon  these  places.  In  addition  to  this,  in 
many  cases,  the  new  wood  from  the  upper  side  of  the  girdled 
spot  was  sufficiently  abundant  to  reach  across  and  form  a  con- 
nection with  the  living  bark  below. 
~ 

Upon  one  of  these  trees  was  found  a  branch  some  four 
inches  in  diameter,  which  had  been  perfectly  girdled  in  1870, 
and,  although  no  communication  had  existed  between  the 
bark  of  the  branch  and  that  of  the  trunk,  it  had  grown  every 
year  till  March,  1874,  when  it  was  cut.  The  buds  upon  it 
were  poorly  developed,  but  alive,  and  the  ends  of  the  branches 
were  dead.  It  apparently  could  not  have  survived  more  than 
a  year  or  two  longer,  and  the  reason  was  obvious  upon  mak- 


PHENOMENA  OF  PLANT-LIFE.  35 

ing  a  longitudinal  section  through  the  girdled  part.  The  limb 
was  nearly  horizontal,  and  the  ring  of  bark  removed  was  only 
a  few  inches  from  the  trunk.  New  layers  had  formed  each 
year  up  to  the  denuded  place,  but  the  enlargement  was  more 
above  this  than  below  it.  The  material  to  form  new  wood 
and  bark  below  came  from  the  other  parts  of  the  tree,  and 
yet,  owing  apparently  to  the  poor  circulation,  was  deficient 
in  quantity.  The  crude  sap  with  some  materials  from  other 
portions  of  the  tree  ascended  to  the  buds  and  leaves,  and  so 
an  unhealthy  growth  was  continued.  An  examination  of  the 
figure  representing  a  section  of  this  branch  will  explain  the 
cause  of  its  final  failure.  The  wood  through  which  the  sap 
must  ascend  was  gradually  dying,  and  thus  the  channel  of 
communication  was  constantly  becoming  more  and  more  ob- 
structed. On  the  whole,  this  method  of  treating  orchards 
cannot  be  recommended  for  general  use.  (Fig.  28.) 

In  regard  to  the  length  of  time  during  which  a  perfectly 
girdled  tree  may  continue  to  live,  we  have  obtained  some 
facts  worth  recording. 

In  India,  it  is  necessary  to  girdle  the  teak  trees  the  year 
before  cutting  them,  in  order  to  have  them  die  and  lose  a 
portion  of  their  sap  by  evaporation,  since  otherwise  the  logs 
will  not  float  down  the  rivers  to  market.  Removing  a  ring 
of  bark  is  not  sufficient  to  accomplish  this  result,  and  it  is 
necessary  to  cut  through  all  the  sap-wood  so  as  to  prevent 
the  ascent  of  water  to  the  leaves. 

Mr.  W.  F.  Flint  has  communicated  an  interesting  account 
of  a  beech  tree  about  eighteen  inches  in  diameter,  which 
grew  in  an  open  pasture  in  Richmond,  New  Hampshire.  It 
was  girdled  for  the  express  purpose  of  killing  it,  in  1866,  by 
chopping  a  gash  two  or  three  inches  wide  and  nearly  as  deep 
entirely  around  the  trunk  near  the  ground.  The  next  year 
it  sent  up  sprouts  from  below  the  girdle  and  formed  a  new 
layer  over  its  entire  surface.  This  was  repeated  in  1867,  but 
in  1868  the  bark  and  sprouts  of  the  lower  part  died,  and  dead 
branches  began  to  appear  in  the  top.  This  process  of  decline 
continued,  and  in  1873  but  one  of  the  large  branches  put 
forth  its  leaves;  and,  finally,  on  the  ninth  year  (1874)  it 
died  utterly.  This  remarkable  tenacity  of  life  is  doubtless 
due  to  the  close,  fine  texture  of  the  timber,  and  the  fact  that 


36  PHENOMENA  OF  PLANT-LIFE. 

such  beeches  in  open  land  have  an  unusual  amount  of  sap- 
wood,  and  are  hence  called  white  beeches. 

A  red  maple,  on  the  College  farm,  which  was  girdled  in 
April,  1873,  by  cutting  a  channel  in  the  sap-wood  two  inches 
wide  and  one  inch  deep,  bled  most  profusely,  but  grew  as 
usual  through  the  season.  No  wood,  however,  was  formed 
below  the  girdle,  and  the  bark  died  and  separated  from  the 
wood.  The  roots,  nevertheless,  remained  alive,  and  the  tree 
has  borne  its  usual  amount  of  foliage  during  the  summer  of 
1874,  and  formed  its  buds  for  next  year,  and  produced  a  new 
layer  of  wood  above  the  girdle.  Specimens  have  been  col- 
lected for  chemical  and  microscopic  analyses  of  the  roots  and 
of  the  wood  and  bark  above  and  below  the  girdle,  in  the  hope 
that  some  light  may  be  thrown  upon  the  subject  of  sap  circu- 
lation and  the  functions  of  the  bark,  whenever  this  work  can 
be  done. 

On  the  third  of  June  last,  branches  of  the  apple,  pear, 
peach,  crab-apple  and  grape  were  girdled  by  removing  a 
ring  of  bark  one  inch  long.  They  grew  well  and  bore  an 
abundance  of  fine  fruit,  as  was  expected. 

On  the  fourth  of  June,  small  trees  of  red  maple,  elm, 
aspen;  willow,  linden,  chestnut,  white  pine,  black  birch,  but- 
ternut, and  a  large  wild  grape  vine,  were  girdled  by  remov- 
ing a  ring  of  bark  two  inches  in  length. 

On  the  twelfth  of  June,  trees  of  ash,  bass,  beech,  black 
birch,  yellow  birch,  white  birch,  alder,  black  oak,  chestnut, 
sugar  maple,  hornbeam  and  ironwood  were  girdled  in  like 
manner;  and  on  the  twenty-third  of  June,  specimens  of  white 
oak,  red  oak,  black  birch,  yellow  birch,  white  birch,  red 
maple,  sugar  maple,  ash,  bass,  aspen,  witch-hazel,  white 
pine,  cornel,  chestnut,  hickory,  beech,  ironwood,  hornbeam, 
apple  and  choke-cherry.  July  twenty-first,  we  girdled  speci- 
mens of  wild  grape,  cornel,  red  maple,  chestnut,  black  birch, 
white  birch,  white  pine,  bitternut,  white  oak  and  black  oak. 

On  the  twenty-eighth  of  August,  the  bark  of  the  following 
species  was  found  to  adhere  to  the  wood,  viz.  :  red  maple, 
yellow  birch,  wild  thorn,  hornbeam,  beech,  witch-hazel,  bird- 
cherry,  white  oak,  red  oak,  elder  and  elm ;  while  the  bark  of 
the  following  species  was  readily  separated  from  the  wood, 
viz.  :  hemlock,  white  pine,  alder,  shadbush,  white  birch, 


PHENOMENA  OF  PLANT-LIFE.  37 

black   birch,    chestnut,    cornel,   ash,    iron  wood,    apple    and 
aspen. 

All  the  trees  thus  girdled  grew  through  the  season  as  usual, 
but  none  of  them  formed  wood  below  the  girdle,  except  the 
grape  and  the  red  maple.  The  former,  being  a  branch  of  a 
large  vine,  with  foliage  both  above  and  below  the  girdle, 
formed  new  wood  on  both  sides  of  it,  and  finally,  the  two 
callouses  were  united  and  communication  restored  across  it. 
(Figs.  29-30.) 

The  red  maple,  girdled  June  23d,  formed  wood  only  on  the 
upper  side,  but  the  specimen  girdled  July  21st,  formed  a 
new  layer  of  wood  and  bark  upon  the  denuded  surface.  This 
was  doubtless  owing  to  the  fact  that  a  portion  of  the  cambium 
was  left  on  the  wood  sufficient  to  conduct  the  elaborated  sap 
and  form  new  tissues  out  of  it.  This  tree,  like  the  others, 
grew  in  the  woods,  where  it  was  shaded  from  the  direct  rays 
of  the  sun.  The  new  bark  was  of  a  reddish  brown  color 
and  very  smooth,  and  consisted  of  a  thin  layer  of  periderm 
or  cork,  with  parenchyma  and  bast.  A  drawing  of  its  micro- 
scopic structure  together  with  one  of  the  old  bark  on  the  same 
tree  has  been  prepared.  (Figs.  -31-34.) 

There  is  a  popular  notion  that  the  bark  of  an  apple  tree, 
removed  on  the  longest  day  of  the  year,  will  be  renewed,  and 
it  is  well  known  that  occasionally  such  renewal  of  the  bark  of 
various  species  does  occur.  This  may  happen  whenever 
there  is  deposited  upon  the  old  wood  enough  of  the  new 
layer  to  conduct  downward  the  elaborated  sap,  and  to  develop 
from  the  living  parenchyma  of  the  forming  medullary  rays  a 
protecting  layer  of  periderm. 

It  is  not  uncommon  for  the  bark  of  the  half-hardy  weeping- 
willow  to  be  started  by  freezing  and  thawing  from  the  wood. 
When  this  is  the  case,  there  sometimes  forms  a  new  layer  of 
wood  upon  the  detached  bark,  which  is  disconnected  from  the 
wood  of  the  parent  trunk.  There  is  also  sometimes  formed  a 
new  layer  of  wood  and  periderm  on  the  old  wood  under  the 
shelter  of  the  old  bark,  and  roots  often  descend  from  the 
healthy  portion  of  the  trunk  several  feet  beneath  the  loose 
bark  to  the  ground,  and  as  soon  as  they  penetrate  it  enlarge 
rapidly.  All  these  phenomena  are  readily  explained  by  sup- 
posing that  the  liber,  or  inner  bark,  of  the  tree  is  torn  asunder, 


38  PHENOMENA  OF  PLANT-LIFE. 

a  portion  sometimes  remaining  attached  to  the  wood  sufficient 
to  conduct  the  elaborated  sap  and  so  form  a  new  layer  of 
wood  with  a  layer  of  bark.  The  roots  are  developed  from  the 
uninjured  portion  under  the  protection  of  the  old  bark,  and  in 
their  nature  are  precisely  like  roots  from  cuttings.  An  in- 
teresting specimen  from  the  grounds  of  Mr.. Charles  S.  Smith, 
of  Amherst,  is  exhibited  in  figure  35. 

The  rupture  of  the  medullary  rays  and  separation  of  the 
bark  from  the  wood  by  the  combined  action  of  frost  and  sun- 
shine is  not  uncommon  in  the  apple  and  other  cultivated 
trees.  If  a  severe  frost  separates  the  water  from  the  wood 
as  ice,  and  it  then  thaws  and  freezes  again  before  it  can  be  re- 
absorbed,  it  will  be  likely  to  burst  the  bark  or  tissues  in 
which  it  is  accumulated.  This  usually  results  in  one  or 
more  cracks  through  the  bark  on  the  southerly  side  of  the 
tree,  from  which  there  is,  in  the  case  of  the  apple  tree,  com- 
monly a  slight  flow  of  crude  sap  in  the  following  April  or 
May.  The  outside  of  the  bark  is  blackened,  and  the  detached 
portions  die. 

In  the  spring  of  1874,  a  vertical  crack  three  feet  long  was 
noticed  in  the1  south  side  of  a  vigorous  young  Graven  stein 
apple  tree  in  Amherst,  the  trunk  of  which  was  about  three 
inches  in  diameter.  Upon  examination,  it  was  found  that  the 
bark  had  not  been  separated  from  the  thick  layer  of  wood 
formed  the  previous  year,  but  that  this  outside  layer  was 
entirely  detached  from  the  wood  beneath.  The  bark,  being 
supplied  with  sap  ascending  through  this  layer,  remained 
sound,  and,  the  crack  having  been  filled  with  wax,  the  tree 
grew  equally  well  with  others  in  its  vicinity  which  had  sus- 
tained no  injury.  The  new  growth  on  the  sides  of  the  crack 
being  covered  only  with  a  thin,  soft  periderm,  will,  doubtless, 
readily  unite,  and  there  will  soon  remain  no  trace  of  the 
rupture.  The  separated  layers  of  wood,  however,  will  never 
be  reunited,  though  the  inner  ones  may  conduct  sap,  until 
converted  into  the  nearly  impervious  heartwood  which  oc- 
cupies the  central  portion  of  every  trunk  after  it  attains  to 
any  considerable  size. 

At  what  age,  if  ever,  the  inner  wood  of  exogens  loses  all 
power  of  conveying  sap,  and  whether  the  sound  heart  of  an 
old  tree  which  has  never  been  exposed  to  the  influences  of  the 


PHENOMENA  OF  PLANT-LIFE.  39 

atmosphere  still  retains  life,  are  questions  which  have  not 
beeii  definitively  answered.  Itvis  not  easy  to  say  wherein  the 
vitality  of  any  perfectly  formed  tissue,  whether  of  the  wood 
or  bark,  consists,  since  their  cells  have  no  power  of  enlarge- 
ment or  multiplication,  though  the  thickening  of  the  cell-walls 
by  the  deposition  of  substances  within  the  cells  and  the  strik- 
ing changes  in  color,  seem  to  indicate  the  presence  of  a  feeble 
life.  The  functions  of  the  wood  seem  to  be  mainly  such  as 
may  be  performed  by  dead  material.  The  cellulose  which  has 
never  been  exposed  to  the  air  may  retain  its  peculiar  affinity 
for  water,  which  is  evidently  much  greater  before  than  after 
drying.  The  cells  may  serve  as  reservoirs  of  starch  and 
other  substances  which  may  afterwards  be  imbibed  by  the 
living,  growing  or  ripening  tissues.  The  pith,  which  is  alive 
in  young  branches  so  long  as  leaves  are  borne  upon  their 
wood,  dies  apparently  with  them.  If  growth  is  a  characteristic 
feature  of  living  tissue,  our  trees  may  with  some  reason  be 
considered  annuals,  since  all  their  growth  proceeds  normally 
from  their  winter  buds  and  completely  envelops  every  portion 
of  the  tissues  of  the  roots,  stems  and  branches  previously 
formed,  thus  excluding  them  from  the  weather  and  pre- 
venting their  decay,  while  using  them  for  a  support  and 
a  magazine  of  supplies.  However  this  may  be,  it  is  cer- 
tain that  the  vitality  of  trees  is  concentrated  in  a  remarkable 
manner  upon  the  surface  and  the  extremities  of  their  roots 
and  branches. 

Among  the  observations  made  during  the  past  season,  not 
the  least  interesting  were  those  relating  to  the  natural  graft- 
ing which  is  frequently  to  be  seen  in  the  forests,  and  which  is 
particularly  noticeable  among  roots.  The  almost  incredible 
manner  in  which  the  living  surface  of  the  inner  bark  of  woody 
stems  can  transform  the  same  elaborated  sap  into  different 
species  of  wood  and  bark,  was  alluded  to  last  year,  and  the 
case  mentioned  of  a  possible  compound  tree,  containing  a 
plum  root  and  base,  on  which  grew  a  stem  of  apricot,  sur- 
mounted by  a  stem  of  blood  peach  with  red  wood,  and  that 
by  a  stem  of  Avhite  peach,  and  the  whole  by  a  stem  and 
branches  of  almond.  Thus,  each  kind  of  wood  and  bark 
would  be  perfectly  developed  from  the  same  material,  just  as 
on  the  same  cow's  milk  may  be  fed  a  child,  a  calf,  a  colt,  a 


40  PHENOMENA  OF  PLANT-LIFE. 

black  pig,  a  white  pig  and  a  lamb.  The  specific  life  of  each, 
and  not  its  food,  determines  its  form,  size  and  character. 

To  show  still  more  impressively  the  peculiar  powers  of  the 
wood  and  bark  to  conduct  the  crude  and  elaborated  saps  in 
either  direction,  and  to  act  either  as  roots  or  branches,  as 
circumstances  require,  we  will  describe  an  experiment  per- 
formed by  a  French  gardener,  M.  Carillet,  at  Vineennes,  in 
1866  and  1867.  He  selected  two  dwarf  pear  trees,  grafted 
on  quince  roots,  which  were  from  four  to  five  feet  high.  One 
of  them  was  carefully  dug  up  in  April,  1866,  and  fastened  in 
an  inverted  position  above  the  other.  The  leading  shoots  of 
the  two  trees  were  now  flattened  on  one  side  with  a  knife, 
and  the  two  surfaces  firmly  bound  together  in  the  usual 
manner  of  splice  grafting.  The  two  shoots  grew  together, 
and,  in  the  course  of  the  summer  following,  a  few  leaves 
appeared  on  the  main  stem  of  the  inverted  pear  tree,  and  also 
on  the  main  branches  of  the  quince  roots,  which  were  entirely 
in  the  air  some  eight  or  ten  feet  from  the  ground.  The  next 
spring,  scions  from  four  varieties  of  pear  were  set  upon  the 
four  main  branches  of  the  quince  roots,  two  of  which  lived 
and  grew  several  inches.  Meanwhile,  the  inverted  pear  tree 
bore  two  pears.  Here,  then,  was  a  composite  tree,  con- 
sisting, first,  of  a  root  of  quince,  then  a  pear  tree,  upon 
this  an  inverted  pear  tree,  which  had  branches  consisting  of 
inverted  quince  roots,  and  these  were  surmounted  by  pear- 
shoots  of  two  unlike  kinds.  Upon  such  a  specimen  it  would 
be  very  difficult  to  comprehend  the  working  of  the  imaginary 
syphons  of  Dr.  Pettigrew,  already  described. 

In  order  to  illustrate  the  fact  that  the  return  of  the  elab- 
orated sap  was  not  the  result  of  the  force  of  gravity,  a  pend- 
ant branch  of  weeping- willow  was  girdled  last  June.  The 
enlargement  was  on  the  lower  side  of  the  girdled  place,  show- 
ing that  the  flow  of  the  material  formed  in  the  leaves  was 
constantly  towards  the  roots.  (Fig.  36.) 

To  learn  whether  sap  •  would  flow  from  the  bark  on  the 
upper  side  of  a  girdled  place,  a  stem  of  white  willow,  an  inch 
in  diameter  and  ten  feet  high,  was  selected,  and  a  ring  of 
bark,  one  inch  long,  removed.  The  girdled  place  was  then 
wrapped  in  oiled  paper,  so  as  effectually  to  exclude  the  air 
and  the  light.  On  the  fifteenth  of  October,  one  month  after 


PHENOMENA  OF  PLANT-LIFE.  41 

girdling,  the  paper  was  taken  off  and  the  specimen  examined. 
The  wood  appeared  dead  and  brown,  and  was  covered  with  a 
mucilaginous  fluid  which  appeared  to  have  come  from- above. 
There  was  no  sign  of  growth  below  the  girdle,  but  above  it 
the  stem  was  decidedly  enlarged,  and  a  callous  had  descended 
a  quarter  of  an  inch  and  developed  upon  itself  a  bud,  as  if 
about  to  strike  out  for  air  and  light.  No  bleeding  from  the 
bark  was  observed  in  any  case  worthy  of  mention,  the  nearest 
approach  to  it  being  in  the  flow  of  turpentine  from  the  bark 
and  sap-wood  of  the  the  white  pine. 

Among  the  specimens  of  natural  grafting  obtained  during 
the  past  year,  perhaps  the  most  remarkable  was  a  fine  bunch 
of  mistletoe,  growing  as  a  parasite  upon  a  branch  of  oak. 
This  was  kindly  procured  for  the  College  museum  by  Prof. 
J.  W.  Mallet,  LL.D.,  of  the  University  of  Virginia.  The 
shrub  is  an  evergreen,  and  its  roots  penetrate  the  bark  and 
sap-wood  of  the  tree  on  which  it  feeds,  appropriating  the 
crude  sap  and  forming  a  wood  of  a  totally  different  sort  from 
that  of  its  support,  and  having  an  ash  peculiar  to  itself.  In 
fact,  the  several  species  on  which  it  is  produced  seem  to  serve 
merely  as  so  many  different  soils  on  which  it  can  thrive.  As 
the  oak-branch  was  dead  beyond  the  mistletoe,  it  would  seem 
to  have  been  injured  by  the  abstraction  of  its  sap  and  its 
exhalation  from  the  foliage  of  the  parasite.  The  singular 
mode  in  which  the  union  is  formed  will  be  understood  by  an 
examination  of  figure  37. 

A  specimen  of  red  maple  was  brought  to  the  College  by 
Mr.  Austin  Eastman,  of  Amherst,  which  exhibited  a  single 
trunk  with  one  heart,  formed  by  the  natural  union  of  two 
shoots,  which  were  nearly  three  feet  apart,  and  were  united 
about  six  feet  from  the  ground.  The  main  trunk  was  eight 
inches  in  diameter. 

Another  specimen,  found  in  Pelham,  shows  two  white  pine 
trunks,  joined  like  the  Siamese  twins,  at  about  four  feet  from 
the  ground.  This,  when  sawed  open  vertically,  showed  how 
the  union  had  been  effected.  A  branch  of  one  had  lodged 
in  the  angle  made  by  a  branch  of  the  other  with  its  parent 
trunk.  As  the  tree  grew,  they  were  fastened  together,  and, 
under  the  pressure  thus  caused,  the  bark  was  flattened  until 
it  almost  disappeared,  and  soon  the  new  wood  formed  over 


42  PHENOMENA  OF  PLANT-LIFE. 

the  scar  and  made  the  grafting  complete.  The  structure  will 
be  understood  by  examining  figure  38. 

But  the  grafting  of  roots  is  still  more  common  and  curious. 
They  seem  to  cohere  without  the  least  difficulty,  especially 
those  of  the  white  pine,  which  is  doubtless  owing  to  the  soft- 
ness of  the  bark  and  young  wood,  and  the  fact  that  they  grow 
so  nearly  at  the  same  level  in  the  earth.  A  specimen  from 
the  vicinity  of  the  College,  exhibiting  a  large  number  of  grafts, 
is  represented  in  figure  39. 

A  branch  of  gray  birch,  which  has  united  with  its  own  trunk 
by  an  attachment  formed  in  the  angle  of  another  branch  above 
it,  is  shown  in  figure  40. 

The  rootward  flow  of  elaborated  sap  is  well  illustrated  in  a 
specimen  of  aspen  in  the  College  museum,  around  which  is 
twined  a  vine  of  bittersweet.  (Figs.  41-42.) 

From  the  observations  above  made,  it  will  be  seen  that  there 
is  no  difficulty  in  accounting  for  the  curious  fact  which  has 
long  been  regarded  as  a  great  mystery,  that  the  stumps  of  fir 
trees,  which  do  not  sprout,  have  been  known  to  continue 
forming  new  layers  of  wood  and  bark  for  a  great  number  of 
years.  Dutrochet  mentions  the  case  of  a  stump  of  the  silver 
fir  which  thus  grew  from  1743  till  1836,  when  it  was  still 
alive,  having  formed,  since  the  tree  was  felled,  ninety-two  thin 
layers  of  wood.  The  roots  of  the  living  stump  were  doubt- 
less grafted  to  the  roots  of  some  healthy  tree  or  trees  in  its 
vicinity,  and  their  elaborated  sap  was  attracted  into  the  sound 
bark  and  supplied  the  necessary  material  for  the  development 
of  new  tissues  under  the  influence  of  its  vital  force.  The 
outer  layer  of  the  roots  of  the  stump  was  thus  renewed  an- 
nually, and  so  they  retained  their  power  of  absorption ;  but 
since  the  top  of  the  stump,  becoming  dry  and  having  no 
foliage,  could  not  exhale  moisture,  the  crude  sap  of  its  roots 
ascended  into  the  neighboring  tree  or  trees  to  which  they 
were  united.  Thus  a  sort  of  circulation  was  maintained 
sufficient  to  explain  the  phenomena  observed. 

Another  peculiarity  often  to  be  seen  in  the  stems  and 
branches  of  trees  and  shrubs,  as  in  the  pear,  the  apple,  the 
hemlock,  and  the  lilac,  is  the  spiral  growth  or  twisting  of  the 
wood  and  bark,  which  is  sometimes  visible  during  the  life  of 
such  specimens,  and  alwa}7s  when  the  bark  is  removed  and  the 


PHENOMENA  OF  PLANT-LIFE.  43 

timber  seasoned.  Some  have  endeavored  to  account  for  this 
phenomenon  by  referring  it  to  the  effect  of  the  wind,  but 
it  is  frequently  seen  on  trees  which  grow  in  sheltered  situa- 
tions. The  timber  of  Pinus  longifolia,  a  valuable  tree  of 
Northern  India,  is  often  rendered  worthless  by  this  habit  of 
growth,  and  while  such  trees  are  more  numerous  in  some 
regions  than  in  others,  they  are  found  irregularly  scattered 
among  those  which  do  not  exhibit  this  abnormal  structure. 
(Fig.  43.) 

The  surprising  phenomena  of  pressure  and  suction  exerted 
upon  mercurial  gauges  attached  to  the  trunks  and  roots  of 
such  trees  as  bleed  or  flow  from  wounds  in  the  spring,  which 
were  described  in  the  paper  presented  to  the  Board  last  year, 
gave  abundant  encouragement  for  further  investigation.  Ac- 
cordingly, numerous  experiments  have  been  undertaken  and 
some  thousands  of  observations  recorded,  which  have  been 
tabulated,  and  are  appended  in  as  compact  a  form  as  possible. 
To  accomplish  so  much  work  as  is  here  represented  in  a  single 
season,  required  the  cordial  cooperation  of  a  considerable 
number  of  persons.  It  is  proper  that  the  names  *of  those 
officers  and  students  of  the  College  who  have  faithfully  and 
intelligently  labored  to  accumulate  these  facts  should  be  an- 
nounced in  connection  with  what  they  have  done.  If  all  who 
enjoy  the  privileges  of  students  in  natural  science  would 
exhibit  the  same  enthusiasm  for  the  acquisition  of  new  truths, 
they  would  thereby  not  only  improve  themselves  but  increase 
the  common  stock  of  knowledge  with  a  rapidity  altogether 
unprecedented. 

Prof.  Levi  Stockbridge  has  made  nearly  all  the  observations 
upon  the  flow  of  sap  in  the  sugar  maple,  and  has  faithfully 
kept  the  record  of  the  variations  of  pressure  in  the  mercurial 
and  water  gauges  on  the  sugar  maple,  the  red  maple  and  the 
butternut,  which  have  been  noted  three  or  more  times  daily 
for  several  months. 

Prof.  S.  T.  Maynard  has  devoted  much  time  to  the  care  of 
the  squash  whose  unparalleled  performances  in  harness  attest 
unmistakably  its  health  and  vigor.  He  has  also  kindly  as- 
sisted in  the  preparation  of  gauges,  and  in  every  way  in  which 
his  services  were  needed.  The  drawings  for  the  cuts  repre- 
senting the  squash  and  the  apparatus  used  in  the  experiments 


44  PHENOMENA  OF  PLANT-LIFE. 

with  it,  as  well  as  for  those  relating  to  the  specimens  of  elm, 
were  furnished  by  him. 

For  the  very  convenient  form  of  stopcocks  used  in  the 
mercurial  gauges,  we  are  indebted  to  the  ingenuity  of  Prof. 
S.  H.  Peabody. 

Much  credit  is  due  to  Mr.  D.  P.  Penhallow,  a  post-graduate 
student,  for  his  untiring  devotion  to  the  study  of  the  squash- 
vine,  with  which  he  spent  many  days  and  nights,  observing 
its  mode  of  growth  and  making  complete  microscopical  draw- 
ings of  all  its  structure.  He  also  adjusted  gauges  to  several 
herbaceous  plants,  and  reported  upon  the  pressure  of  their 
saps.  He  assisted  in  finding  the  per  cent,  of  water  in  various 
species  of  wood  at  different  seasons  of  the  year,  and  his 
pencil  prepared  all  the  drawings,  except  those  already  men- 
tioned. 

Charles  Wellington,  B.S.,  assistant  in  the  chemical  labor- 
atory, has  undertaken  to  determine  the  composition  of  various 
saps  and  the  effect  on  them  of  the  advancing  season.  This 
important  investigation  is  not  yet  completed. 

Mr.  Walter  H.  Knapp,  with  great  fidelity,  furnished  the 
material  for  the  table  showing  the  amount  of  sap  which  flowed 
daily  from  each  species. 

Mr.  Atherton  Clark  made  the  observations  on  the  water 
gauges,  except  that  on  the  sugar  maple,  on  the  mercurial 
gauges  in  the  case  of  the  white  birch  root,  the  apple  root  and 
the  three  on  the  grape  vine,  one  of  which  was  thirty  feet 
from  the  ground.  He  also  did  much  of  the  work  relating  to 
the  time  when  each  species  begins  to  flow. 

Mr.  William  P.  Brooks  began  and  carried  out  very  thor- 
oughly a  series  of  observations  to  learn  precisely  what  species 
flowed,  at  what  time  in  the  season,  and  how  rapidly,  visiting 
for  this  purpose  about  forty  species  daily  for  several  weeks. 
In  some  unaccountable  manner,  the  memorandum  book  con- 
taining most  of  his  records  has  been  lost,  and  so  his  report  is 
incomplete. 

Mr.  Henry  Hague  recorded  the  variations  on  the  mercurial 
gauges  upon  the  four  birches,  one  of  them  thirty  feet  from 
the  ground  ;  and  on  the  hornbeam,  three  times  daily  for  many 
weeks. 

Mr.  George  R.  Dodge  attended  to  a  series  of  experiments 


PHENOMENA  OF  PLANT-LIFE.  45 

instituted  to  determine  the  circumstances  which  affect  the 
flow  of  sap  from  the  maples,  and  furnished  an  excellent 
report. 

It  has  been  said  that  all  species  of  flowering  plants  will 
probably  bleed  from  some  part,  if  wounded,  at  some  time  of 
their  growth.  This  has  not  been  demonstrated,  and  some 
trees  seem  to  have  a  wood  so  remarkably  spongy  and  reten- 
tive of  moisture  as  to  render  it  unlikely  that  they  should  ever 
flow.  Much  effort  has  been  made  to  arrive  at  the  truth  on 
this  subject  concerning  our  common  forest  trees  by  methods 
detailed  below. 

About  the  middle  of  last  March,  a  large  number  of  trees 
were  selected  and  prepared  for  observation  by  boring  one 
half-inch  hole  to  the  depth  of  two  inches  into  the  wood,  and 
inserting  a  galvanized  iron  sap-spout,  invented  by  Mr.  C.  C. 
Post,  of  Burlington,  Vt.,  and  well  adapted  for  use  in  the 
sugar-bush.  The  species  thus  tapped,  and  all  others  named 
in  this  paper,  will  be  mentioned  by  their  common  English 
names,  which  are  familiar  to  most  persons  ;  but,  in  order  that 
these  may  be  clearly  understood,  a  list  is  appended  contain- 
ing both  the  English  and  the  Latin  names.  The  following 

o  o  o 

were  tested,  as  above  described,  for  sap,  viz.  :  hemlock, 
black  spruce,  balsam  fir,  alder,  European  alder,  striped 
maple,  red  maple,  sugar  maple,  shad-bush,  white  birch, 
black  birch,  yellow  birch,  paper  birch,  hornbeam,  chestnut, 
hickory,  bitternut,  cornel,  thorn,  quince,  ash,  beech,  butter- 
nut, black  walnut,  mulberry,  ironwood,  white  pine,  yellow 
pine,  buttonwood,  aspen,  English  cherry,  black  cherry, 
mountain  ash,  apple,  pear,  peach,  white  oak,  red  oak,  glau- 
cous willow,  white  willow,'  bass,  linden,  elm  and  grape. 
These  trees  were  visited  every  day,  about  noon,  for  several 
weeks,  the  holes  being  renewed  as  often  as  necessary,  and 
whenever  they  were  found  flowing  the  number  of  drops  per 
minute  was  recorded,  except  in  the  case  of  such  trees  as 
flowed  somewhat  abundantly  and  for  a  considerable  time. 
The  whole  amount  of  sap  from  those  of  the  latter  class  was 
carefully  collected  and  weighed  daily.  A  reference  to  the 
table  appended  will  give  at  a  glance  the  principal  results, 
such  as  the  dates  of  the  beginning  and  end  of  the  flow,  and 
the  total  amount  from  each- species.  It  will  be  seen  that  the 


46  PHENOMENA  OF  PLANT-LIFE. 

sugar  maple  flows  at  any  time  when  stripped  of  its  foliage, 
provided  the  weather  is  favorable,  the  principal  condition 
being  a  temperature  above  freezing,  directly  after  severe 
frost.  A  comparison  of  the  flow  from  this  species  with  the 
pressure  on  the  mercurial  gauges,  and  with  the  temperature 
as  indicated  in  the  meteorological  observations,  kindly  furn- 
ished by  Prof.  E.  S.  Snell,  LL.D.,  of  Amherst  College,  will 
convince  the  inquirer  that  there  is  an  intimate  connection 
between  these  three  sets  of  facts. 

The  quantity  of  sap  from  a  sugar  maple  during  the  season 
is  much  greater  than  from  any  other  tree  flowing  from  the 
same  causes.  Thus  the  entire  flow  from  the  butternut  was 
less  than  the  product  of  the  sugar  maple  for  a  single  day. 
The  ironwood  and  the  birches,  however,  surpass  even  the 
maple,  both  in  the  rapidity  and  amount  of  their  flowing,  if  we 
make  allowance  for  the  difference  in  the  size  of  the  trees  tested. 
A  paper  birch,  fifteen  inches  in  diameter,  flowed  in  less  than 
two  months  one  thousand  four  hundred  and  eighty-six  pounds 
of  sap ;  the  maximum  flow,  on  the  fifth  of  May,  amounting 
to  sixty-three  pounds  and  four  ounces,  which  is  probably 
three  times  the  average  yield  of  a  sugar  maple  of  the  same 
size.  These  latter  species  will  not  bleed  during  the  winter, 
and  seem  to  do  so  in  the  spring  from  a  cause  entirely  difier- 
ent  from  that  which  affects  the  trees  which  bleed  in  fall  and 
winter.  The  grape,  which  is  often  thought  to  bleed  more 
freely  than  any  other  species,  though  later  in  the  season,  really 
flows  but  little,  the  total  amount  from  a  very  large  vine  being 
eleven  pounds  and  nine  ounces. 

Among  the  species  subjected  to  trial,  only  those  mentioned 
as  bleeding  exhibited  this  phenomenon.  The  following  flowed 
for  a  short  time,  or  very  irregularly,  or  very  slowly.  The 
shad-bush  was  seen  to  flow,  on  the  eighth  of  April,  one  drop 
in  fifty  seconds.  The  hickory  bled  one  drop  per  minute  of 
very  sweet  sap,  on  the  fifteenth  of  April,  and  the  cornel,  ten 
drops  on  the  same  day.  The  European  alder  flowed  three 
drops  per  minute,  April  ninth,  and  the  common  alder,  four 
drops,  on  the  twenty-first  of  March,  and  on  the  tenth  of  April, 
nine  drops  from  one  spout  and  six  drops  from  another,  in- 
serted six  inches  below  the  former.  The  black  walnut  yielded 
a  small  amount  of  sap  during  several  weeks,  and,  March 


PHENOMENA  OF  PLANT-LIFE.  47 

thirtieth,  bled  six  drops  per  minute.  The  buttonwood  flowed 
forty  drops  per  minute,  March  twenty-fifth,  and  one  hundred 
on  a  very  cold  day,  the  eighth  of  April.  The  total  amount, 
however,  was  very  small.  The  apple  bled  twenty-eight  drops 
per  minute,  May  thirteenth,  and  the  beech,  on  the  tenth  of 
May,  flowed  ten  drops  per  minute,  both  yielding  most  sap  in 
decidedly  warm  weather,  the  mean  temperature  for  the  last 
date  being  above  70°  F.  The  latex  of  the  mulberry  exuded 
from  the  bark,  on  the  ninth  of  April,  as  a  transparent  fluid 
which  soon  became  milky,  and  the  white  and  yellow  pines 
flowed  a  small  quantity  of  turpentine,  apparently  from  both 
bark  and  wood. 

A  large  red  maple,  which  was  thoroughly  girdled  in  1873, 
and  whose  bark  had  died  and  peeled  off  below  the  girdled  place, 
was  tapped  above  and  also  below  it.  The  result  was  that  it 
bled  freely  from  both  holes  on  many  occasions.  The  flow,  on 
the  eighth  of  April,  was  fifty  drops  per  minute  from  the  upper 
one,  and  one  drop  from  the  lower  one,  while  on  the  eleventh 
of  the  same  month,  it  was  three  drops  from  the  upper  and 
fourteen  drops  from  the  lower  one. 

After  the  usual  run  of  sap  for  the  season  has  ceased,  some 
species  will  bleed  from  the  stump,  if  cut  down,  just  like  many 
herbaceous  plants.  Thus,  Mr.  Win.  F.  Flint  reports  that 
large  trees  of  the  black,  yellow,  and  paper  birch,  when  felled 
on  the  thirtieth  of  June  last,  did  not  bleed  immediately,  as  in 
April,  but  after  an  hour  or  two  began  to  exude  sap  freely. 

On  August  twenty-eighth,  twenty-four  species  of  young 
trees  were  cut  down,  about  one  foot  from  the  ground,  to  see 
whether  they  would  bleed.  None  did  so  immediately,  but 
fifteen  hours  afterward  the  black  birch  ran  a  few  drops,  and 
the  following  were  moist  on  the  top  of  the-  stump,  viz.  :  alder, 
yellow  birch,  red  maple,  cornel,  ironwood,  apple,  elder,  elm, 
and  white  pine.  August  thirty-first,  the  black  birch  bled  a 
little,  and  the  yellow  birch,  thorn,  apple,  glaucous  willow,  elm, 
and  white  pine  were  moist.  The  rest,  including  hemlock, 
shad-bush,  white  birch,  chestnut,  hornbeam,  beech,  ash,  witch- 
hazel,  bird  cherry,  white  oak,  red  oak,  and  aspen,  were  per- 
fectly dry,  though  all  were  sheltered  from  the  sun. 

These  results  seem  to  include  most  of  the  important  attain- 
able facts  in  regard  to  the  flow  of  sap  as  exhibited  by  our  com- 


48  PHENOMENA  OF  PLANT-LIFE. 

mon  exogenous  trees,  and,  while  none  of  the  observations  can 
be  exactly  repeated  from  the  nature  of  the  phenomena,  yet 
they  may  safely  be  accepted  as  the  substantial  truth  concern- 
ing the  whole  subject. 

The  interesting  facts  observed  last  year,  in  connection  with 
the  attachment  of  mercurial  gauges  to  the  roots  and  trunks  of 
trees  which  were  known  to  bleed  from  wounds,  and  the  sug- 
gestions derived  from  them,  were  a  powerful  stimulus  to  fur- 
ther investigations  in  this  direction.  Accordingly,  a  large 
number  of  gauges  were  prepared  in  early  spring,  and,  as  soon 
as  the  weather  was  suitable,  attached  to  such  trees  and  roots 
as  gave  promise  of  the  most  valuable  results. 

There  still  remained  the  unaccountable  fact  that  the  larger 
number  of  trees  and  shrubs  did  not  show  any  tendency  to 
bleed  in  spring,  and  therefore  could  not  be  made  to  answer 
any  inquiries  put  to  them  in  regard  to  the  circulation  of  sap. 
It  was  thought  best  to  adopt  a  cheaper  and  simpler  form  of 
gauge  for  application  to  such  species  as  gave  small  promise  of 
useful  results.  For  this  purpose,  the  following  economical 
apparatus  was  devised  and  applied  to  the  roots  of  elm,  ash, 
white  oak,  chestnut,  apple,  sugar  maple,  and  hickory.  A 
straight  glass  tube,  three  feet  in  length,  with  a  bore  about  one 
quarter  of  an  inch  in  diameter,  was  joined  by  a  conical  rubber 
connector  with  each  of  the  detached  roots,  and  the  roots  again 
covered  with  the  earth  in  which  they  grew.  The  tubes  were 
now  fastened  in  a  vertical  position  to  stakes  set  near  the  ends 
of  the  detached  roots,  which  were  one  inch  in  diameter.  They 
were  then  filled  with  water  to  a  certain  point,  which  was  care- 
fully marked,  and  the  changes  occurring  noted  every  day. 
Sometimes  the  water  in  a  tube  would  sink  away,  showing  an 
absorption  of  the  fluid  by  the  roots ;  and  again  it  would  rise 
and  flow  over  the  top  of  the  tube,  demonstrating  the  fact  that 
the  absorbing  power  of  the  root  was,  sometimes  at  least,  in 
excess  of  the  affinity  of  the  cellulose  of  the  wood  for  water. 
It  was  well  established  that  the  wood  of  the  roots  of  trees  is  in 
a  condition  in  early  spring  to  absorb  with  avidity  the  water 
from  the  tubes,  while  later  in  the  season  many  of  them  exude 
water  freely,  so  as  to  cause  the  tubes  to  overflow.  The 
amount  of  absorption  was  recorded  in  inches,  the  minus  sign 
being  prefixed  to  the  numbers,  while  the  exudation  was  meas- 


PHENOMENA  OF  PLANT-LIFE.  49 

ured  in  a  similar  way,  with  the  omission  of  the  sign.  Thirty- 
six  inches  of  water  in  one  of  these  tubes  weighed  one  ounce, 
and  from  these  data  it  was  easy  to  learn  the  actual  amount  of 
water  which  was  taken  up  or  thrown  off  daily  by  each  species. 
The  table  of  observations  for  six  common  trees,  which  is  ap- 
pended, will  convey  a  correct  impression  of  the  peculiarities 
of  this  phenomenon. 

One  of  the  most  remarkable  discoveries,  in  this  connection, 
is  the  entirely  unexpected  fact  that  the  roots  of  the  sugar 
maple  do  not  exude  any  sap  from  their  wood  when  protected 
from  frost,  and  show. less  independent  power  of  absorbing 
water  from  the  soil  than  almost  any  other  species.  Hence, 
there  was  no  flow  from  the  root  into  the  tube  at  any  time, 
but  a  constant  moderate  absorption  of  water  from  it. 

The  flow  from  the  root  into  the  tube  is  similar  to  that 
observed  in  the  tube  of  an  ordinary  osmometer  ;  but  this  does 
not  prove  that  osmose  has  any  influence  in  this  matter,  and 
the  doubt  about  it  is  not  diminished  when  we  see  the  water 
moving,  sometimes  in  one  direction  and  sometimes  in  another. 
In  the  sugar  maple,  the  flow  was  always  out  of  the  tube  into 
the  wood  of  the  root ;  in  the  white  oak,  the  absorption  from 
the  tube  was,  in  some  cases,  as  much  as  one  ounce  in  thirty 
minutes,  but  rarely  the  current  was  reversed  and  absorption 
occurred  from  the  ground ;  while,  in  the  elm,  the  absorption 
from  the  tube  was  at  its  maximum,  April  fifteenth,  and  then 
gradually  diminished  until  April  twenty-first,  from  which  date 
the  flow  into  the  tube  continued  till  June  thirtieth,  when  the 
observations  were  suspended. 

A  section  of  a  white  oak  root,  eight  inches  long  and  one 
inch  in  diameter,  which  was  freshly  dug  from  the  damp  earth, 
April  eleventh,  and  weighed,  was  then  placed  with  one  end 
in  water  three-eighths  of  an  inch  in  depth,  and  in  ten  hours 
absorbed  3.19  per  cent,  of  its  weight.  This  shows  that  the 
tissues  were  far  from  saturated,  and  were  in  an  excellent  con- 
dition to  facilitate  ordinary  root  absorption.  A  mercurial 
gauge  attached  to  a  root  of  white  oak  showed  on  the  twelfth 
of  April  a  suction  sufficient  to  sustain  a  column  of  water  10.20 
feet  in  height,  which  was  caused  by  the  absorption  of  the 
water  in  the  connecting  tube  between  the  gauge  and  the  root. 

The  mercurial  gauge,  which  was  used  for  determining  the 


50  PHENOMENA  OF  PLANT-LIFE. 

variations  of  the  pressure  exerted  by  the  sap  of  such  species 
as  are  noted  for  the  abundance  of  their  flow,  consisted  of  a 
syphon-tube  of  thick  glass,  the  two  legs  of  which  were  eight 
feet  long,  and  about  four  inches  apart.  This  was  inverted 
and  attached  to  a  support  of  inch  board,  on  the  centre  of 
which  was  fastened  a  scale  divided  to  tenths  ot  an  inch.  To 
one  leg  of  the  tube  at  the  top  was  adjusted  a  brass  stopcock, 
by  means  of  small  rubber  hose,  and  to  the  stopcock  was  con- 
nected by  a  brass  coupling  a  piece  of  thick  lead  pipe  of  small 
bore  and  convenient  length,  which  was  joined  by  another 
stopcock  to  the  trunk,  root,  or  branch  which  was  to  be 
tested.  The  stopcocks  were  so  made,  with  a  tube  on  the  top, 
that  communication  could  be  opened  between  the  free  air  and 
either  the  lead  or  the  glass  tubing  at  pleasure,  and,  when 
closed  from  the  air,  the  passage  was  open  between  the 
mercury  in  the  syphon-tube,  the  water  in  the  lead  pipe  and 
the  sap  in  the  tree.  The  object  of  this  three-way  cock  was 
to  facilitate  filling  the  tubes  with  water  and  mercury,  and 
allowing  the  escape  of  any  gas  which  might  find  its  way  into 
the  apparatus  from  the  tree.  A  sufficient  quantity  of  mercury 
was  poured  into  the  inverted  syphon  to  fill  the  two  legs  to  the 
height  of  about  forty  inches,  and  the  remainder  of  the  leg 
connected  with  the  tree,  as  well  as  the  lead  pipe,  was  care- 
fully filled  with  water,  all  air  being  excluded.  The  other  leg 
of  the  syphon-tube  was  left  open  to  the  atmosphere.  When 
the  sap  exerted  a  pressure,  it  was  indicated  by  a  depression  of 
the  mercury  in  the  closed  leg  of  the  glass  tube  and  a  rise  in 
the  open  end,  the  difference  between  the  two  columns  showing 
the  pressure  in  inches  of  mercury.  Suction  into  the  tree  was 
marked  by  the  rise  of  the  mercury  in  the  closed  leg  and  its 
depression  .in  the  open  one,  and  in  making  the  record  the 
minus  sign  was  prefixed  to  the  figures  expressing  the  number 
of  inches  of  mercury. 

One  of  the  difficulties  encountered  in  these  experiments 
arose  from  the  liability  to  leakage,  either  around  the  stopcock 
inserted  into  the  tree,  or  from  accidental  wounds  to  the  bark 
or  small  branches.  In  cases  where  the  pressure  was  very 
great,  it  was  sometimes  necessary  to  solder  a  heavy  sheet  of 
lead  to  the  stopcock  and  nail  it  to  the  tree  with  a  packing  of 
white  lead  in  oil.  Much  trouble  was  also  experienced  from 


PHENOMENA  OF  PLANT-LIFE.  51 

the  bursting  of  the  lead  pipes  and  the  breaking  of  the  glass 
tubes  during  severe  cold  weather  by  the  formation  of  ice 
within  the  gauges.  To  avoid  this  as  much  as  possible,  the 
gauges  were  enclosed  in  wooden  cases,  and  the  more  exposed 
portions  wrapped  in  woollen  blankets. 

Mercurial  gauges  were  attached  to  the  following  species, 
viz.  :  sugar  maple,  red  maple,  black,  yellow,  white  and  paper 
birches,  ironwood,  apple  and  grape,  and  all  the  observations 
may  be  found  in  the  appended  tables.  The  general  results 
correspond  with  those  of  last  year,  but  are  much  more  com- 
plete, especially  in  regard  to  the  two  species  which  exhibit 
the  most  surprising  phenomena  and  in  which  the  public  feel 
the  deepest  interest,  namely,  the  sugar  maple  and  the  grape 
vine. 

As  soon  as  the  discovery  was  made,  by  means  of  the  water 
gauge,  that  the  apple  would  flow  from  the  root,  a  mercurial 
gauge  was  attached  to  a  root  an  inch  in  diameter.  At  first, 
on  the  fifteenth  of  May,  there  was  a  slight  suction  amounting 
to  -1.59  feet  of  water ;  but  the  pressure  soon  began,  and  rose 
to  its  maximum,  May  thirty-first,  when  it  equalled  15.07  feet 
of  water.  Thus,  the  extreme  variation  was  16.66  feet. 

The  butternut  had  a  range  of  only  13.03  feet,  the  minimum, 
-0.79  foot,  occurring  on  April  tenth,  and  the  maximum,  12.24 
feet,  on  April  fourteenth. 

The  red  maple  attained  its  minimum,  -2.83  feet,  April  six- 
teenth, and  its  maximum,  18.59  feet,  April  eighth,  the  total 
variation  being  21.42  feet  of  water. 

The  ironwood  exerted  its  greatest  suction  on  the  nineteenth 
of  May,  which  equalled  -24.60  feet,  while  the  greatest  pressure 
was  40.35  feet,  and  was  observed,  May  thirteenth.  The  total 
variation  was  thus  64.95  feet  of  water. 

The  white  birch  began  early  in  the  season,  April  ninth; 
reached  its  minimum,  -19.26  feet,  on  the  eleventh  of  May,  and 
its  maximum,  39.66  feet,  April  twenty-third.  The  extreme 
variation  was,  therefore,  58.92  feet  of  water. 

A  gauge  was  attached  to  a  root  of  white  birch  on  the  eighth 
of  April;  the  pressure  began,  April  twelfth,  and  steadily  ad- 
vanced to  its  highest  point,  38.08  feet,  May  twelfth,  and 
declined  to  zero,  May  twenty-third,  and  to  its  minimum, 
-22.98  feet,  August  twenty-sixth,  the  extreme  variation 


52  PHENOMENA  OF  PLANT-LIFE. 

amounting  to  61.06  feet  of  water.  The  root  was  dug  up  in 
October  aiid  found  apparently  alive  and  healthy. 

The  black  birch  root  last  year  exerted  the  astonishing  pres- 
sure of  84.77  feet  of  water,  but  was  not  observed  through  the 
season.  This  year,  on  the  eighth  of  April,  a  guage  was 
adjusted  to  a  root  of  the  same  tree,  and,  although  the  pressure 
was  not  quite  as  great  as  last  season,  the  extreme  variation 
was  102.68  feet.  The  first  pressure  was,  April  twenty-third, 
and  the  highest,  May  tenth,  and  equalled  77.06  feet,  while  the 
greatest  suction  was  on  September  fourteenth,  and  amounted 
to  -25.62  feet  of  water. 

The  pressure  is  evidently  caused  in  these  roots,  which  are 
entirely  detached  from  the  tree  and  lie  in  the  earth  just  as 
they  grew,  by  the  activity  of  their  power  of  absorption,  which 
seems  to  be  greatest  just  as  the  buds  are  about  bursting.  The 
suction  is  remarkably  powerful,  and  must  apparently  result 
from  some  chemical  change  occurring  in  the  root,  after  the  root- 
fibres  have  lost  their  absorbing  power.  A  critical  examination 
by  the  chemist  and  the  microscopist  would  probably  give  an 
explanation  for  this  phenomenon. 

The  paper  birch  tree  reached  its  maximum,  May  sixth,  when 
the  pressure  was  equal  to  sustaining  a  column  of  water  61.20 
feet  in  height.  The  suction  on  June  fourteenth  was  —7.93 
feet,  and  the  extreme  variation  for  the  season  was  69.13  feet. 

On  the  eighth  of  April,  a  gauge  was  attached  to  a  yellow 
birch  tree  near  the  ground,  and,  on  the  twenty-fourth,  at 
noon,  the  pressure  was  73.67  feet  of  water.  A  hole  was  then 
bored  into  the  tree  at  a  height  of  thirty  feet  above  the  lower 
one,  for  the  purpose  of  putting  up  another  gauge.  The  mer- 
cury in  the  lower  gauge  fell  at  the  rate  of  four  inches  per 
minute,  till  it  stood  at  a  point  representing  35.13  feet  of  water. 
The  sap,  at  the  same  time,  flowed  freely  from  the  upper  orifice. 
The  usual  difference  between  the  gauges  thus  placed  thirty 
feet  apart  was  from  twenty-four  to  thirty-five  feet  of  water, 
showing  evidently  that  the  power  furnishing  the  pressure  was 
from  below,  that  is,  from  the  root.  The  maximum  of  the 
lower  gauge  was  74.22  feet,  April  twenty-second,  and  the 
minimum  was  -22.44  feet,  May  sixteenth,  and,  hence,  the  total 
variation  was  96.66  feet.  The  upper  gauge  attained  a  pressure 
of  41.25  feet,  on  the  ninth  of  May,  and  sank  to  -11.11  feet  on 


PHENOMENA  OF  PLANT-LIFE.  53 

the  thirteenth  of  May,  the  extreme  variation  being  52.36  feet 
of  water.  After  the  development  of  the  buds,  the  upper  gauge 
stood  uniformly  at  from  -1  to  -4  feet  of  water,  and  the  lower 
one  was  mostly  minus. 

The  bleeding  of  a  broken  grape  vine,  in  1720,  induced  the 
Rev.  Stephen  Hales,  an  ingenious  observer  of  nature,  to  at- 
tach mercurial  manometers  to  the  stumps  of  vine  branches 
and  stems,  by  means  of  which  he  obtained  a  maximum  press- 
ure of  forty-three  feet  of  water.  These  experiments  were 
made  on  vines  of  the  species  Vitis  vim/era,  in  the  compara- 
tively cool  and  moist  climate  of  England.  It  is,  therefore, 
not  surprising,  that  the  more  vigorous  Vitis  cestivatis,  in  the 
more  fervid  and  sunny  climate  of  Massachusetts,  should  exert 
a  greatly  superior  force.  In  order  to  determine  as  many  facts 
as  possible  concerning  the  flow  and  pressure  of  the.  sap  of  the 
wild  summer  grape,  two  of  the  largest  vines  on  tpe  College 
estate  were  selected  and  prepared  for  observation^  The 
smaller  one  was  about  three  inches  in  diameter  at  th&  ground, 
and  spread  over  a  young  elm,  some  forty  feet  in  height,  and 
standing  in  moist,  open  land.  One  of  the  main  roots  of 
the  vine  was  uncovered  and  followed  from  the  stem  toward 
its  extremities,  a  distance  of  four  feet,  where  it  was  cut  off. 
To  the  large  end  of  this  detached  root,  the  remainder  of 
which  was  left  undisturbed  in  the  soil  as  it  grew,  was 
firmly  fastened  a  piece  of  stout  rubber  hose,  which  was  con- 
nected by  means  of  a  stopcock  to  the  lead  pipe  of  a  mercu- 
rial gauge.  This  was  on  May-day.  The  tissues  of  the  root, 
which  had  not  yet  awakened  from  its  winter  sleep,  at  once 
began  to  absorb  the  water  from  the  gauge,  and  the  next  day 
there  appeared  a  suction  equal  to  -4.53  feet  of  water.  This 
continued,  though  gradually  diminishing,  till  it  reached  zero, 
on  the  tenth  of  May.  From  this  time  the  pressure  still  in- 
creased until,  on  the  twenty-ninth  of  the  month,  it  became 
sufficient  to  sustain  a  column  of  water  88.74  feet  in  height, 
which  is  more  than  twice  as  great  as  the  maximum  observed 
by  Hales,  and  the  greatest  pressure  ever  produced  by  the  sap 
of  a  plant  so  far  as  we  know.  It  is  an  interesting  fact  that 
this  maximum  occurred  on  the  warmest  day  in  May,  the  mean 
temperature  having  been  71.7°  F.  It  is  also  noteworthy  that, 
on  the  very  day  when  the  gauge  first  showed  pressure,  the 

8 


54  PHENOMENA  OF  PLANT-LIFE. 

vine  which  was  tapped  began  to  flow,  though  it  was  half  a 
mile  distant.  The  pressure  on  the  gauge  steadily  diminished 
through  the  season,  and,  on  the  fourteenth  of  September, 
amounted  to  19.35  feet.  The  extreme  variation  was  93.27 
feet  of  water,  and,  therefore,  9.41  feet  less  than  in  the  case 
of  the  black  birch  root,  which  exhibited  a  much  greater  suc- 
tion, though  less  pressure,  than  the  grape  root. 

The  other  vine  selected  for  trial  was  nearly  four  inches  in 
diameter  and  more  than  fifty  feet  high.  To  a  large  branch 
of  this,  near  the  ground,  was  attached  a  gauge  by  means  of 
a  rubber  hose,  the  branch  being  cut  oif  for  that  purpose.  A 
second  gauge  was  secured  to  another  branch  at  the  height  of 
thirty  feet  above  the  first,  and  observations  made  upon  them, 
once,  twice,  or  three  times,  daily ,  from  May  seventh  till  June 
thirtieth.  After  this,  occasional  visits  were  made  to  the  vine, 
though  the  variations  were  very  slight.  The  pressure  on  the 
lower  gauge  began  on  the  seventh  of  May,  when  it  was  11.11 
feet  of  water*  and  reached  its  maximum  on  the  twenty-sixth 
of  the  month,  equalling  a  column  of  water  83.87  feet  in  height. 
The  pressure  declined  quite  rapidly  as  soon  as  the  buds  be- 
gan to  develop,  and  fell  to  zero,  June  thirteenth.  The  greatest 
suction  was  exhibited  on  the  twenty-ninth  of  June,  and  was- 
equal  to  sustaining  a  column  of  water  14.39  feet  high.  Dur- 
ing the  month  of  July,  when  growth  was  most  rapid,  the  suc- 
tion was.  uniformly  about  -7.37  feet  of  water,  and,  during 
August,  about  -4  feet.  The  extreme  variation  on  this  gauge 
amounted  to  98.26  feet,  though  the  pressure  was  somewhat 
less  than  was  shown  by  that  on  the  detached  root  of  the  vine 
already  mentioned. 

The  upper  gauge  was  not  reached  by  the  sap  rising  from 
the  root  until  some  days  after  pressure  was  manifest  at  the 
lower  one.  On  the  twelfth  of  May,  the  lower  one  stood  at 
34.11  feet  of  water,  and  the  upper  at  3.40  feet.  The  max- 
imum pressure  was  attained,  May  sixteenth,  and  was  39.66  feet, 
while  the  greatest  suction  occurred,  June  twentieth,  and  was 
-10.77  feet.  The  extreme  variation  of  the  upper  gauge  was 
50.43  feet.  The  difference  between  the  two  gauges  was  usu- 
ally from  20  to  30  feet  of  water  ;  but  when  the  pressure  on  the 
lowrer  one  was  greatest,  the  difference  was  60.41  feet,  in  con- 
sequence of  the  fact  that  the  force  was  entirely  from  the  root, 


PHENOMENA  OF  PLANT-LIFE.  55 

and  the  wood  of  the  vine  was  a  hindrance  to  the  sudden 
upward  thrust  of  the  sap.  After  the  foliage  was  developed, 
the  suction  was  limited  to  from  -^6  to  -12  feet  of  water,  on 
account,  doubtless,  of  tire  porous  character  of  the  foliage  and 
young  branches,  and  there  was  no  great  difference  between 
the  gauges. 

The  flow  of-  sap  from  the  sugar  maple,  so  familiar  to  all, 
and  yet  so  variable  and  peculiar,  was  the  first  object  of  inves- 
tigation in  the  beginning  of  these  experiments,  in  1873,  but 
its  mysterious  fluctuations  were  not  fully  known  nor  under- 
stood until  the  close  of  the  year  1874.  The  extraordinary 
fac^s,  that  the  flow  occurred  in  mid-winter  and  early  spring, 
when  the  ground  was  covered  with  snow  and  there  were  no 
signs  of  life ;  that  the  flow  began  only  during  mild  days 
immediately  following  a  severe  frost,  and  ceased  usually  after 
a  few  hours ;  that  when  a  cavity  was  cut  into  a  sugar  maple 
tree,  the  sap  flowed  down  from  above,  while  in  a  birch  it 
flowed  most  freely  from  below ;  and  especially  the  fact,  that 
when  a  gauge  was  attached  to  a  tree,  it  exhibited  the  most 
surprising  variations  from  great  pressure,  during  the  day,  to 
powerful  suction  at  night, — these,  and  other  unaccountable 
things,  seemed  to  demand  special  effort  to  discover  all  the 
phenomena  attending  the  flow  of  maple  sap ;  and  then,  if 
possible,  to  invent  some  rational  explanation  of  them. 

Accordingly,  a  large  number  of  experiments  were  devised 
and  carried  out,  with  a  very  great  amount  of  labor  and  no  little 
expense.  Among  them  were  the  collection  and  weighing  of 
all  the  sap  which  would  flow  from  a  healthy  tree,  from  Novem- 
ber to  the  following  May,  with  a  careful  observation  of  the 
times  when  the  flow  began  and  ceased,  in  each  case  of  good 
sap-weather  ;  the  collection,  weighing  and  analysis  of  sap  dur- 
ing different  periods  of  the  entire  season,  both  from  the  usual 
level  and  from  the  top  of  a  tree  thirty  feet  from  the  ground ; 
the  collection  and  examination  of  the  gas  which  escapes  with 
the  first  flow  of  sap  from  the  orifice  first  made  m  a  tree  in  the 
spring ;  the  effect  of  increasing  the  number  of  holes  upon  the 
total  flow  of  sap  and  the  entire  product  of  sugar ;  the  result 
of  tapping  trees  at  various  elevations  from  the  earth,  on 
different  sides,  and  to  different  depths ;  and  finally,  a  record 
for  comparison  and  study  of  the  fluctuations  in  the  mercury 


56  PHENOMENA  OF  PLANT-LIFE. 

of  several  gauges,  attached  to  various  parts  of  the  same  tree, 
as  observed  three  or  more  times  daily. 

Upon  reference  to  the  table  showing  the  flow  of  sap  from 
the  sugar  maple,  it  will  be  noticed  that  the  tree  (No.  1) 
tapped  near  the  ground  flowed  quite  freely  in  December  and 
January  as  well  as  in  March  and  April,  the  total  amount  of 
sap  being  five  hundred  and  sixty-six  pounds  and  twelve 
ounces.  Notwithstanding  the  large  quantity  previously  ex- 
uded, the  flow  from  this  tree  during  the  month  of  April 
amounted  to  one  hundred  and  four  pounds  and  eight  ounces, 
while  a  tree  (No.  2)  nearly  as  large,  from  which  no  sap  had 
been  taken,  but  which  was  tapped  at  the  height  of  thirty ffeet 
from  the  ground,  bled  only  fifty-five  pounds  and  eleven  ounces. 
It  is  evident,  therefore,  that  the  flow  is  greatest  at  the  lowest 
point,  other  things  being  equal ;  but  it  often  happens  that  the 
sap  will  drop  from  a  broken  twig  in  the  top  of  a  tree  when  it 
will  not  run  at  all  from  the  trunk. 

Mr.  Samuel  F.  Perley,  of  Naples,  Maine,  in  an  interesting 
communication  containing  much  valuable  information  derived 
from  his  large  experience  in  the  sugar-bush,  relates  the  fol- 
low ing  incident  :  "Happening,  on  a  bright,  sunny  morning,  to 
visit  a  sugar  tree  standing  in  open  land,  and  having  a  large, 
spreading  top,  I  was  surprised,  on  walking  beneath  the  limbs, 
to  find  quite  a  smart  shower  falling  upon  me.  On  looking 
up,  I  could  see  no  clouds,  yet  the  drops  were  falling  thick 
and  fast  in  all  the  area  covered  by  the  branches  of  the  tree. 
An  examination  showed  the  drops  to  be  drops  of  sap  flowing 
from  innumerable  broken  twigs.  I  then  remembered  that  a 
day  or  two  before  there  had  been  a  storm  of  sleet  and  rain, 
which  had  encased  the  trees  with  a  heavy  coating  of  ice,  and 
following  that,  a  violent  wind  which  had  twisted  and  broken 
many  of  the  smaller  branches.  From  these  was  now  flowing 
a  brilliant  shower  of  sap,  sparkling  in  the  bright  sunshine.  I 
could  not  perceive  that  this  wholesale  tapping  diminished  at 
all  the  flow  from  the  trunk,  or  in  any  manner  injured  the 
tree." 

Icicles  of  frozen  sap  are  not  unfrequently  seen  depending 
from  the  branches  of  maple  and  butternut  trees  during  severe 
cold  weather,  when  the  temperature  rises  only  slightly 
above  32°  F.  at  mid-day.  On  Thanksgiving  Day,  1874,  the 


PHENOMENA  OF  PLANT-LIFE.  57 

thermometer,  in  the  shade,  indicated  32°  F.  at  two  P.  M. 
A  sugar  maple  was  tapped  'at  the  ground,  and  fifty  feet  above 
it,  and  while  there  was  no  flow  from  the  lower  orifice,  the 
upper  one  bled  four  drops  per  minute. 

On  the  twentieth  of  November  last,  the  weather  was  cold, 
and  at  eleven,  A.  M.  there  was  a  rapid  fall  of  soft  snow,  fol- 
lowed by  a  rising  temperature.  At  half-past  twelve,  P.  M., 
the  mercurial  gauge,  in  the  top  of  a  sugar  maple,  indicated  a 
pressure  of  about  nine  feet  of  water,  while  u  gauge  at  the 
ground  showed  neither  pressure  nor  suction. 

In  the  case  of  a  tree  tapped  in  1873,  on  the  north  and  south 
sides,  in  order  to  compare  the  flow  from  each,  it  was  found 
that,  for  some  reason,  the  north  spout  yielded  nearly  twice  as 
much  sap  as  the  south  one,  and  flowed  two  weeks  longer.  It 
appears  probable  that  this  was  an  exceptional  instance,  and 
possibly  to  be  accounted  for  by  the  fact,  that  the  roots  of  the 
south  side  ran  under  a  highway,  while  those  of  the  north  side 
luxuriated  in  a  rich  meadow. 

In  1874,  another  tree,  about  sixty  feet  in  height  and  four 
feet  and  ten  inches  in  girth,  was  subjected  to  the  same  trial. 
The  total  flow  from  the  south  side  was  eighty-six  pounds  and 
four  ounces,  while  that  from  the  north  side  was  sixty-eight 
pounds  and  five  ounces.  Near  the  close  of  the  season  only, 
did  the  flow  from  the  latter  exceed  that  from  the  former. 
There  can  be  no  doubt  that  it  is  much  wiser  to  tap  all  sugar 
trees  on  the  south  side,  because  the  sap  will  flow  earlier  and 
more  abundantly  than  from  the  shaded  side,  while  the  late 
sap  is  of  little  value  to  the  sugar-maker. 

Another  sugar  maple,  seventy  feet  high  and  four  feet  in 
circumference,  was  tapped  on  the  south  side  in  five  places, 
the  holes  being  two  feet  apart  on  a  vertical  line,  so  that  spout 
number  one  was  near  the  ground,  number  two,  directly  above 
number  one,  number  three,  two  feet  above  number  two,  and 
so  on.  During  the  month  of  April,  the  sap  from  each  spout 
was  weighed  daily,  and  the  results  were  as  follows,  viz.  : 
The  total  flow  was  one  hundred  and  twenty  pounds  and  one 
ounce.  From  number  one,  near  the  ground,  was  collected 
seventy-eight  pounds  and  ten  ounces ;  from  number  two, 
twelve  pounds  and  two  ounces ;  from  number  three,  five 
pounds  and  ten  ounces ;  from  number  four,  eight  pounds  and 


58  PHENOMENA  OF  PLANT-LIFE. 

seven  ounces  ;  and  from  number  five,  fifteen  pounds  and  four 
ounces.  These  facts  are,  in  the  main,  what  would  be 
expected  from  the  other  observations  made  concerning  the 
flow  of  maple  sap. 

The  effect  of  increasing  the  number  of  spouts  inserted  into 
a  tree  was  tried  on  two  red  maples,  which  flow  much  less  than 
the  sugar  maple  and  for  a  shorter  time.  Ten  spouts  in  one 
tree,  sixty  feet  high  and  four  feet  eight  inches  in  girth,  were 
found  to  flow,  during  the  first  half  of  April,  seventy-eight 
pounds  and  eight  ounces,  while  one  spout  in  a  similar  tree 
flowed  less  than  half  as  much,  or  thirty-five  pounds  and  two 
ounces.  There  can  be  no  doubt  that  the  quantity  of  sap 
obtained  from  a  tree  by  the  use  of  many  spouts  is  greater 
than  that  from  a  limited  number,  but  it  is  not  likely  to  contain 
so  large  a  per  cent,  of  sugar.  Still,  if  it  be  true,  as  seems 
probable,  that  the  withdrawal  of  sap  exerts  no  deleterious 
influence  upon  the  health  and  vigor  of  a  tree,  and  the  sap  is 
richest  early  in  the  season,  it  would  seem  best  to  insert  more 
spouts,  and  so  extract  the  sugar  in  its  purest  condition  as 
rapidly  as  possible*  This,  of  course,  would  necessitate  a 
greater  expenditure  for  buckets,  which  might  possibly  coun- 
terbalance the  advantages  of  the  new  method.  Experiments 
might  be  easily  instituted  to  determine  the  facts  in  regard  to 
this  matter  by  any  intelligent  sugar-maker. 

In  regard  to  the  origin  of  cane  sugar  in  the  sap  of  the 
maples,  the  butternut  and  the  black  walnut,  we  must,  for  the 
present,  admit  that  we  have  not  yet  discovered  it ;  though 
the  singular  fact  that  the  species  which  yield  this  sugar  belong 
to  that  class  of  trees  which  only  flow  freely  after  severe  frost 
seems  to  indicate  that  freezing  and  thawing  may  have  some 
influence  upon  its  production. 

It  will  be  seen,  from  an  examination  of  the  table  relating 
to  the  composition  of  saps,  that  the  sap  of  the  wild  grape  is 
almost  pure  water,  and  that  it  contained,  on  the  fifteenth  of 
May  last,  no  trace  of  either  cane  sugar,  glucose  or  starch. 
There  is,  however,  in  the  wood  of  the  roots  and  stems  of  the 
genus  Vitiss.  great  quantity  of  a  colorless,  translucent,  almost 
tasteless  mucilage,  which  is  abundantly  exuded  from  the  pores 
of  a  c»oss  section  made  at  any  time  when  the  roots  are  dor- 
mant. Very  little  even  of  this  seems  to  escape  from  a  bleed- 


PHENOMENA  OF  PLANT-LIFE.  59 

ing  vine,  which  may  account  for  the  fact  that  the  flow  of  crude 
sap  from  the  grape  does  not  perceptibly  affect  its  subsequent 
growth  or  productiveness. 

The  sap  of  the  sugar  maple  contains  from  two  to  three  per 
cent,  of  cane  sugar,  while  that  of  the  red  maple  yields  only 
about  half  as  much.  The  sap  of  the  latter  is  said  by  Mr.  H. 
M.  Sessions,  of  Wilbraham,  also  to  contain  some  ingredient 
which  attacks  iron,  forming  a  very  dark-colored  syrup  when 
evaporated  in  pans  of  that  metal.  It  is,  therefore,  better  to 
exclude  it  from  the  sap  gathered  for  the  manufacture  of 
sugar. 

In  order  to  obtain  as  much  information  as  possible  in  regard 
to  the  sap  of  the  sugar  maple,  an  analysis  was  made  of  the 
gas  contained  in  the  tree  when  first  tapped.  This  was  pro- 
cured by  inserting  a  stopcock  into  the  sap-wood  of  a  tree 
twenty  feet  from  the  ground.  To  the  stopcock  was  attached  a 
glass  tube  by  means  of  a  rubber  connector  and  the  tube  passed 
through  a  cork  into  a  large  bottle,  reaching  to  the  bottom. 
As  soon  as  the  bottle  was  filled  with  sap,  it  was  tightly  closed 
and  taken  to  the  laboratory,  where  the  gas  was  separated  by 
boiling.  The  analysis  shows  that  the  gas  contains  much  less 
nitrogen  and  more  oxygen  than  atmospheric  air,  while  the 
proportion  of  carbonic  acid  gas  is  about  one  hundred  and 
thirty-four  times  greater  in  the  former  than  in  the  latter. 

As  we  do  not  know  how  or  when  the  cane  sugar  is  formed 
in  the  mnple,  we  cannot  account  for  the  variations  in  the 
sweetness  of  its  sap,  which  are,  however,  very  great.  As 
the  flow  depends  upon  the  freezing  and  thawing  of  the  wood, 
and  possibly  upon  the  continuance  of  absorption  by  the  roots 
to  supply  the  drain  upon  the  tapped  tree,  it  is  evident  that  a 
large  body  of  snow  upon  the  ground  will  favor  it,  since  the 
e;irth  will  then  be  warmer  and  the  night  temperature  of  the 
air  much  colder  than  under  other  circumstances.  It  does  not 
appear  that  there  is  any  greater  proportion  of  sap  in  the 
maple  than  in  many  other  trees,  but  only  that  for  some 
unknown  reason  it  is  separated  in  greater  quantity  by  freezing, 
or  else  not  reabsorbed  after  such  separation  so  quickly  as  in 
other  species. 

For  the  purpose  of  learning  whether  root  absorption  is 
necessary  to  keep  up  the  flow  of  sap  through  the  season,  a 


60  PHENOMENA  OF  PLANT-LIFE. 

large  tree,  sixty  feet  in  height  and  four  feet  and  a  half  in 
girth,  was  cut  early  in  December,  1874,  and  firmly  lashed  in  an 
upright  position  to  neighboring  trees.  A  fire  was  then  kin- 
dled around  the  lower  end  of  the  trunk,  in  order  to  dry  and 
close  as  far  as  possible  the  pores  of  the  wood.  Next  spring 
it  is  proposed  to  apply  mercurial  gauges  to  determine  whether 
the  sap  moves,  as  in  trees  in  a  natural  condition,  and  after- 
ward to  collect  and  analyze  the  sap. 

•  While  it  is  certain  that  the  flow  of  the  grape  and  the  birch 
results  from  the  great  activity  of  the  absorbing  rootlets  when 
they  first  awake  in  spring  from  their  winter's  repose,  it  seems 
equally  evident  that  root  absorption  has  no  direct  connection 
with  the  flow  of  maple  sap.  This  discovery  was  made  by 
means  of  five  mercurial  gauges,  which  were  attached  with 
great  care  to  a  fine,  vigorous  tree,  about  sixty  feet  in  height, 
on  the  twentieth  of  last  March.  The  gauges  were  so  con- 
nected with  all  parts  of  the  tree  that  every  movement  of  the 
sap  would  be  indicated.  Number  one  was  joined  to  a  stop- 
cock inserted  into  the  sap-wood  about  two  feet  from  the  ground, 
the  hole  being  about  one  inch  in  diameter  and  two  inches  deep. 
Number  two  was  connected  by  a  stout  rubber  hose  to  a  root 
one  inch  in  diameter,  which  was  laid  bare  by  the  use  of  a 
force-pump,  so  as  to  avoid  breaking  any  of  its  fibres.  This 
root  was  cut  open  at  the  distance  of  about  two  feet  from  the 
tree,  and  gauge  number  two  united  to  the  stump,  which  was 
attached  to  the  trunk.  Number  three  was  joined  in  the  same 
way  to  the  large  end  of  the  detached  root,  which  remained  in 
the  soil,  just  as  it  grew.  Number  four  was  fastened  .to  a  piece 
of  gas-pipe  one  inch  in  diameter,  which  was  screwed  into  the 
tree  to  the  depth  of  ten  inches,  a  thread  having  been  cut  for 
this  purpose  on  the  outside  of  it.  No  sap  could  enter  this 
gauge  except  at  the  very  centre  of  the  heart- wood  of  the  trunk. 
Number  five  was  attached  to  the  sap-wood  among  the  branches, 
at  an  elevation  of  twenty  feet  above  gauge  number  one.  The 
gauges  thus  connected  were  then  inclosed  in  tight  pine  cases, 
and  the  metallic  pipes  and  stopcocks  wrapped  in  woolen 
blankets  to  protect  them  from  the  cold.  The  observations 
were  taken  regularly  at  six  A.  M.,  at  noon,  and  at  six  P.  M., 
for  about  ten  weeks,  until  the  changes  became  unimportant. 
The  table  appended  gives  all  the  variations  of  sap  pressure 


PHENOMENA  OF  PLANT-LIFE.  61 

in  different  parts  of  the  tree,  as  recorded  at  the  times  speci- 
fied. A  reference  to  figure  44  will  convey  a  correct  idea  of 
the  manner  in  which  the  mercury  fluctuates  during  every  hour 
of  the  day  and  night. 

The  following  are   some  of  the   most   interesting   results 
obtained  from  the  several  gauges : — 


GAUGE. 

Minimum. 

Date  «f 
Minimum. 

Maximum. 

Date  of 

Maximum. 

Extreme  Variation. 

Gauge  1, 

—18.13 

Apr.  11, 

39.67 

Mar.  28, 

57.80  feet  of  water. 

"      2,       . 

—7.71 

M      4, 

36.27 

"    28, 

43.98     " 

"      3,       . 

—7.71 

Mar.  21, 

3.40 

Apr.   3, 

11.11     " 

"       4,       , 
"      5,       . 

—6.01 
—26.07 

Apr.  22, 
Mar.  31, 

22.33 
52.13 

Mar.  28, 
Apr.   2, 

28.34    " 

78.20     " 

The  wood  of  the  detached  root  absorbed  the  water  from  the 
gauge,  so  as  to  exert  a  suction,  like  the  roots  of  most  other 
species  of  trees  in  early  spring,  but  the  pressure  exhibited  at 
any  time  was  scarcely  worthy  of  mention.  So  strange  did 
this  appear,  that,  on  the  fourth  of  April,  the  gauge  was  re- 
moved to  a  healthy  root,  detached  from  another  tree,  and,  to 
avoid  any  possibility  of  error,  it  was  afterward  connected  with 
a  third  root,  but  the  results  were  always  similar.  It  is  cer- 
tain, therefore,  from  these  observations,  as  well  as  those  con- 
nected with  the  water-gauge,  described  on  a  preceding«page, 
that  the  rise  and  flow  of  maple  sap  is  not  directly  caused  by 
the  activity  of  absorbent  rootlets. 

Secondly ;  it  is  seen  that  the  movements  of  the  sap  in  the 
heart  of  a  tree  are  much  less  rapid  and  vigorous  than  those 
occurring  in  the  sap-wood  at  the  same  level.  This  is  doubt- 
less owing  to  the  fact  that  the  old  wood  is  more  dense,  and 
therefore  less  permeable  to  fluids  than  the  outer  layers  of 
alburnum ;  and  also  to  the  circumstance  that  the  variations 
of  temperature,  at  the  depth  of  ten  inches  from  the  bark,  are 
necessarily  slow  and  limited. 

Finally  ;  it  remains  to  consider  the  extraordinary  fact,  that 
the  greatest  suction,  as  well  as  the  highest  pressure,  was 
exhibited  by  the  gauge  in  the  top  of  the  tree.  On  the  eigh- 
teenth of  April,  the  lower  gauge  in  the  sap-wood  indicated  a 


62  PHENOMENA  OF  PLANT-LIFE. 

pressure  equal  to  10.77  feet  of  water,  while,  at  the  same  time, 
the  upper  gauge  showed  a  pressure  of  24.93  feet.  On  the 
thirty-first  of  March,  the  gauges  were  all  frozen,  number  one 
standing  at  28.90  feet  of  water,  while  number  five  indicated 
a  suction  equal  to  -26.07,  a  difference  of  54.97  feet.  In  the 
case  of  number  one,  attached  to  the  trunk  near  the  ground,  it 
seemed  that  the  gauge  froze  before  the  body  of  the  tree  was 
much  chilled,  while,  by  the  sudden  freezing  of  the  branches, 
the  sap  was  abstracted  from  the  upper  gauge  before  the  cold 
had  penetrated  the  coverings  sufficiently  to  freeze  it. 

On  the  nineteeth  of  April,  the  upper  gauge  showed  little  or 
no  pressure,  while  the  lower  one  still  indicated  a  pressure  of 
17  feet.  This  was  apparently  due  to  the  absorption  of  the 
sap  from  the  branches  by  the  expanding  buds. 

In  view  of  all  the  phenomena  thus  far  observed,  it  appears 
that  the  flow  of  sap  from  the  maple  and  other  species,  which 
bleed  only  after  being  frozen,  is  in  no  sense  a  vital  process, 
but  purely  physical.  The  sap  is  separated  from  the  cellulose 
of  the  wood  by  the  cold,  and,  under  ordinary  conditions, 
gradually  reabsorbed.  If,  however,  the  tree  be  tapped,  so 
that  the  liberated  sap  can  escape,  then  it  will  do  so,  flowing, 
as  is  readily  seen  to  be  the  case  with  the  maple,  most  copiously 
from  above.  The  bleeding  is,  therefore,  a  sort  of  leakage 
from  the  vessels  of  the  wood,  but  this  is  doubtless  increased 
by  the  elastic  force  of  the  gases  in  the  tree,  which  are  com- 
pressed by  the  liberated  sap,  and  this  expansive  power  must 
be  intensified  by  the  increase  of  temperature  which  always 
accompanies  a  flow. 

This  theory  explains  the  fluctuations  of  the  gauges,  and 
accounts  for  the  singular  fact  that  the  upper  one  shows  the 
most  pressure  and  the  greatest  variations,  inasmuch  as  the 
branches  and  twigs  would,  of  course,  be  most  quickly  and 
powerfully  affected  by  the  heat  of  the  sun  and  the  tempera- 
ture of  the  atmosphere.  The  pressure  of  the  expanded  gases 
in  a  tree  in  a  normal  condition  would  facilitate  the  re-absorp- 
tion by  the  wood  of  the  liberated  sap.  Their  contraction  by 
cold  would  also  cause  the  cessation  of  the  flow  from  a  tree 
which  was  running,  and  produce  the  remarkable  phenomenon 
of  suction  exhibited  by  the  gauges  at  night  or  during  frosty 
weather. 


PHENOMENA  OF  PLANT-LIFE.  63 

An  important  and  elegant  demonstration  of  this  theory  was 
obtained  by  cutting  large  branches,  fifteen  to  twenty  feet  in 
length,  when  the  thermometer  was  below  zero,  from  trees  of 
the  sugar  maple,  white  birch,  elm,  hickory,  button  wood, 
chestnut  and  willow,  and  suspending  them  in  the  warm  air  of 
the  Durfee  Plant-House.  The  maple  soon  began  to  bleed  at 
the  rate  of  twenty-four  drops  per  minute,  while  the  button- 
wood  bled  eleven  drops,  and  the  hickory  exuded  a  little  very 
sweet  sap,  precisely  as  in  spring.  The  birch,  elm,  chestnut* 
and  willow  did  not  flow  at  all,  and  were  not  even  moist  on 
the  freshly-cut  surface. 

A  mercurial  gauge,  attached  to  the  end  of  a  frozen  branch 
of  sugar  maple,  indicated  pressure  and  suction  when  the  tem- 
perature was  raised  ancl  lowered,  precisely  as  it  would  have 
done  upon  a  maple  tree  during  the  ordinary  alternations  of 
day  and  night  in  the  spring  of  the  year  when  the  sap  is 
flowing. 

In  the  warm  regions  of  Asia,  Africa  and  America,  are  found 
about  one  thousand  species  of  palm  trees,  from  many  of 
which  a  sweet  sap  is  obtained  in  large  quantities.  This  is 
simply  allowed  to  ferment,  and  drank  as  palm-wine  or  toddy, 
or  distilled  for  the  production  of  a  sort  of  brandy,  or  it  is 
evaporated  for  the  extraction  of  its  sugar  in  the  form  of  syrup, 
or  of  a  more  or  less  crystalline  solid  called  jaggery.  In  the 
province  of  Bengal,  in  India,  more  than  one  hundred  million 
pounds  of  palm-sugar  are  manufactured  annually,  while  the 
total  product  of  palm- wine  in  the  world  greatly  exceeds  that 
of  wine  from  the  grape. 

There  are  three  principal  methods  adopted  in  different 
countries  for  obtaining  the  sweet  sap  of  palms.  In  Chili, 
trees  fifty  feet  high  are  felled  in  such  a  way  that  the  top  will 
lie  higher  than  the  butt  of  the  trunk,  and  the  single  terminal 
bud  with  the  crown  of  leaves  is  cut  off".  The  sap  flows  abun- 
dantly from  the  higher  end  of  this  log,  and  if  a  fresh  slice  of 
wood  be  removed  every  day  the  bleeding  continues  for 
several  months.  The  yield  is  greatest  during  the  warmest 
days,  and  amounts  in  all  to  an  average  of  ninety  gallons,  or 
about  seven  hundred  and  twenty-five  pounds,  from  each  tree. 
This  sap  is  mostly  evaporated  and  utilized  as  a  very  agreeable 
syrup  called  palm-honey. 


64  PHENOMENA  OF  PLANT-LIFE. 

In  India,  it  is  customary  to  make  incision  into  the  wood  of 
trees  near  the  top,  from  which,  during  the  cool  months,  the  sap 
flows  freely.  From  the  common  wild  date-palm  the  annual 
yield  of  sap  is  about  two  hundred  pounds,  containing  some 
eight  pounds  of  sugar,  or  four  times  the  average  product  of 
the  sugar  maple.  Much  the  larger  proportion  of  palm  sap  is 
obtained,  however,  from  the  large  branching  flower-stalks  of 
^the  inflorescence.  These  are  produced  in  the  axils  of  the 
immense  leaves  or  fronds,  and  before  they  burst  the  spat-he  in 
which  they  are  enveloped,  they  are  carefully  bound  together 
with  pieces  of  palm-leaf.  These  buds  are  then  beaten  every 
morning  with  sticks  and  a  thin  slice  removed  from  the  tip  of 
the  axis  of  inflorescence.  From  the  freshly  exposed  surface 
the  sweet  sap  runs  very  abundantly  for  several  months. 
Indeed,  some  species  continually  send  out  new  flower-stalks, 
which  are  constantly  bled  until,  after  two  or  three  years,  the 
tree  dies  from  exhaustion. 

But  the  most  remarkable  flow  of  sap  is  that  of  the  Agave 
Americana,  or  century  plant.  This  is  the  largest  herbaceous 
plant  known,  the  leaves  of  one  in  the  Durfee  Plant-House 
being  eight  feet  long  and  of  immense  weight.  In  Mexico,  the 
sap  of  this  species  furnishes  the  favorite  beverage  of  the 
people.  This  is  called  pulque,  and  has  a  most  detestable  odor 
of  carrion  and  a  slightly  'acid  taste.  The  Mexicans  are  very 
fond  of  it,  and  natives  of  other  countries  soon  learn  to  love  it 
and  then  prefer  it  to  claret.  The  sap  is  procured  by  cut- 
ting out  the  bud  of  the  inflorescence  which  appears  in  the 
centre  of  the  massive  crown  of  leaves,  and,  if  undisturbed, 
develops  into  a  flower-stalk  from  thirty  to  forty  feet  high  and 
covered  with  thousands  of  blossoms.  The  cavity  made  by 
removing  the  bud  is  speedily  filled  with  a  sweet  sap,  and  the 
total  amount  from  one  plant  is  stated  by  Von  Humboldt  to  be 
from  tvfelve  to  sixteen  hundred  pounds.  The  plant  then 
dies  from  exhaustion. 

It  is  impossible  to  give  any  satisfactory  explanation  for 
these  extraordinary  phenomena.  It  is  easy  to  state  that 
these  plants  produce  large  quantities  of  starch  and  sugar  pre- 
paratory to  flowering,  but  why  should  they  continue  to  flow 
so  long  after  the  trees  are  cut  down  or  the  flower  buds 
removed  ? 


PHENOMENA  OF  PLANT-LIFE. 


65 


If  it  be  true  that  the  sap  of  plants  flows  to  the  points  of 
consumption,  it  is  still  difficult  to  explain  why  it  should  per- 
sistently tend  upward  to  the  top  of  a  prostrate- trunk,  or  of  a 
standing  tree,  for  months  after  the  bud,  for  the  special  nourish-* 
ment  of  which  it  is  designed,  has  been  destroyed,  and  after 
the  process  of  growth  has  been  entirely  suspended. 

It  is  evident,  in  conclusion,  that  there  yet  remains  ample 
room  for  investigation  concerning  the  phenomena  connected 
with  the  development  of  plants  and  the  circulation  of  sap. 
Though  we  cannot  hope  to  exhaust  the  subject,  or  to  discover 
precisely  what  the  force  is  which  we  call  life,  and  which 
imparts  to  eveiy  species  and  individual  of  the  vegetable  world 
its  peculiar  form  and  characteristics,  it  is  none  the  less  impor- 
tant and  interesting  to  exercise  our  utmost  ingenuity  in  the 
effort  to  discover  the  times  and  modes  of  its  operation,  and 
its  relations  to  the  other  forces  of  Nature. 


LATIN  AND  COMMON  NAMES  OF  SPECIES. 


Abies  balsamea,      .        .  Balsam  Fir. 

Finns  longifolia, 

Chir. 

A.  Canadensis,      .        .  Hemlock. 

P.  riffida, 

Yellow  Pine. 

A.  nigra,        .        .        .  Black  Spruce. 

P.  Strobus,  . 

White  Pine. 

A.  Picea,        .        .        .  Silver  Fir. 

Platanus  occidentalis,  . 

Buttonwood. 

Acer  Pennsylvanicum,  Striped  Maple. 

Populus  tremuloides,   . 

Aspen. 

A.  ritbrum,     .        .        .  Red  Maple. 

Prunua  Amygdalus,    . 

Almond. 

A.  saccharinwn,    .        .  Sugar  Maple. 

P.  Armeniaca,     . 

Apricot. 

Alnus  incana,        .        .  European  Alder. 

P.  Avium,    . 

English  Cherry. 

A.  serrulata,          .        .  Alder. 

P.  domestica, 

Plum. 

Amelanchier  Canadensis,  Shad  Bush. 

P.  Pennsylvania, 

Bird  Cherry. 

Bettila  alba  var.  popu- 

P.  Persica,  . 

Peach. 

lifolia.        .        .        .  White  Birch. 

P.  serotina,  . 

Wild  Cherry. 

B.  lenta,         .        .        .  Black  Birch. 

P.  Virginiana, 

Choke  Cherry. 

B.  lutea,         .        .        .  Yellow  Birch. 

Pyrus  aucuparia, 

Mountain  Ash. 

B.  papyracea,        .        .  Paper  Birch. 

P.  baccata,  . 

Siberian  Crab. 

Carpimis  Americana,    .  Hornbeam. 

P.  Malus,     . 

Apple. 

Castanea     vesca.     var. 

Quercus  alba, 

White  Oak. 

Americana,         .        .  Chestnut. 

Q.  coccinea  var.  tincto- 

Carya  alba,    .        .        .  Hickory. 

ria,    . 

Black  Oak. 

C.  amctra,       .        .  ^     .  Bitternut. 

Q.  rubra, 

Red  Oak. 

Cornus  alternifolia,       .  Cornel. 

Salixalba,   . 

White  Willow. 

Cratcegus  coccinea,         .  Thorn. 

S.  Babylomca,     . 

Weeping  Willow. 

Cydonia  vulgaris,          .  Quince. 

S.  discolor,  . 

Glaucous  Willow. 

Fagus  ferruginea,         .  Beech. 

Syringa  vulgaris, 

Lilac. 

Fraximus  Americana,   .  Ash. 

Tectona  grandis, 

Teak. 

Juglans  cinerea,     .        .  Butternut. 

Tilia  Americana, 

Bass. 

/.  nigra,         .        .        .  Black  Walnut. 

T.  Europea,  .        .        . 

Linden. 

Morus  alba,    .        .        .  Mulberry. 

Ulmus  Americana, 

Elm. 

Ostrya  Virginica,  .        .  Ironwood. 

Vitis  cestivalis, 

Grape. 

Phoradendronflavescens,  Mistletoe. 

V.  vinifera,  . 

European  Grape. 

66 


PHENOMENA  OF  PLANT-LIFE. 


TABLE 

Showing  the  date  and  amount  of  the  Flow  of  Sap  from  species  which 
bleed  somewhat  freely,  with  dimensions  of  specimens  under  observation. 


NAME. 

Height, 

Girth, 

feet. 

feet.  in. 

Acer  Pennsylvanicum,   . 

22 
60 

1 
6    10 

A.  saccharinum,  No.  2,  . 

60 

5      6 

Betula  alba  var.  populifolia,  

40 

2     4 

B.  lenta,  

57 

4     2 

B.  lutea,  

58 

3     1 

B.  papyracea,  

75 

3     9 

Carpinus  Americana,     

16 

8 

Juglans  cinerea,     

51 

4     2 

Ostrya  Virginica,    ........ 

54 

2     2 

Vitis  aestivalis,       .        

35 

8 

Total  amount  of  $ap  collected  from  the  following  species  during  the 
season  of  1874. 


DATE.   ' 

Pounds. 

Ounces. 

Acer  saccharinum,  from  Dec.  16,  1873,  to  Apr.  30,  1874, 
A.  saccharinum,  (30  feet  from  ground)  from  April  1, 
to  May  1,    
A.  Pennsylvanicum,  from  Mar.  23,  to  May  4, 
Betula  alba  var.  populifolia,  from  Mar.  23,  to  May  23, 
B,  lenta,  from  Mar.  29,  to  May  29,         .... 

566 

55 
15 
127 
397 

12 

11 
15 

6 

7 

B.  lutea,  from  Apr.  3,  to  May  27,  

949 

9 

B.  papyracea,  from  Mar.  29,  to'  May  26,       ... 
Carpinus  Americana,  from  Apr.  9,  to  May  22, 
Juglans  cinerea,  from  Mar.  23,  to  May  18,    . 
Ostrya  Virginica,  from  Apr  16,  to  May  26,  . 
Vitis  aestivalis,  from  May  11,  to  June  3, 

1,486 
6 
18 
279' 
11 

13 
13 

9 

PHENOMENA  OF  PLANT-LIFE. 


67 


Flow  of  Sap. 


DATE. 

Acer  Pennsyl-  1 
vanicum. 

Betula  alba  var.  1 
populifolia. 

Juglans  cinerea.  1 

83 

1 

Betula  lenta. 

Acer  sacchari- 
num. 

<S 

Is 

i 

Carpinus  Ameri-  1 
cana. 

OstryaVirginica.  I 

1874. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Mar.  23, 

5 

1  2 

10 

_ 

_ 

_ 

_ 

— 

_ 

26, 

14 

7 

1  10 

- 

- 

- 

- 

- 

- 

27, 

4 

6 

1  5 

- 

- 

- 

- 

- 

- 

28, 

13 

2 

9 

- 

- 

- 

- 

- 

29, 

1 

2  11 

7 

3 

1 

- 

- 

- 

- 

30, 

4 

1  8 

8 

- 

- 

- 

- 

- 

- 

31, 

13 

2  4 

1  1 

2 

- 

- 

- 

- 

- 

Apr.   1, 

2 

2  2 

5 

2 

- 

2 

- 

- 

- 

2, 

9 

1 

2 

- 

- 

4  7 

- 

- 

- 

3, 

5 

2 

10 

1 

- 

7  15 

2 

- 

- 

4, 

10 

2  15 

10 

11 

2 

- 

1  10 

- 

- 

5, 

_ 

1  2 

_ 

10 

1  1 

1 

2 

- 

- 

6, 

8 

1 

6 

2 

2 

4 

2 

- 

- 

7, 

15 

4 

11 

4 

10 

5  2 

1  12 

_ 

- 

8, 

1  9 

3  10 

6 

1  11 

2  13 

8  8 

5  4 

- 

- 

9, 

3 

7  15 

1  3 

4  14 

6  7 

7 

8  5 

1  3 

- 

10, 

3 

9  8 

•  IS 

9  2 

8 

- 

9  2 

1 

- 

11, 

7 

10  12 

5 

9  9 

11  4 

1  4 

13 

3 

- 

12, 

- 

9  1 

5 

12  9 

14  4 

- 

14  8 

- 

- 

13, 

6 

- 

1 

1 

12  4 

1  4 

6  2 

- 

- 

14, 

6 

4 

10 

2  4 

7  12 

7  12 

8  6 

- 

- 

15, 

1 

6  10 

12 

14  13 

16  11 

1  10 

18  14 

_ 

- 

16, 

3 

9  2 

4 

25  5 

20  10 

_ 

27 

_ 

1 

17, 

1 

10 

- 

28  9 

22  2 

- 

25  7 

1 

2  15 

18, 

1 

4  13 

1 

27  14 

20  14 

3  7 

19  6 

- 

1  3 

19, 

1  10 

7  1 

15 

38  1 

20  4 

8 

31  4 

- 

- 

20, 

11 

8  14 

47  1 

22  2 

1  2 

47 

- 

2  14 

21, 

5 

7  10 

11 

57  2 

12  10 

8 

54  9 

1 

2  1 

22, 

4 

7  7 

1 

51  2 

5  12 

- 

31  8 

- 

12 

23, 

4 

7  3 

5 

53  13 

5  14 

•  - 

21  5 

- 

14 

24, 

1 

5  11 

3 

51  5 

6  3 

- 

15  13 

_ 

2 

25, 

3 

5  15 

2 

58  7 

6  4 

- 

13  6 

- 

12 

26, 

1 

2  2 

1 

53  11 

6  14 

3  6 

10  2 

- 

4 

27, 

15 

'3  5 

9 

56  2 

5  7 

— 

8  15 

- 

1 

28, 

3 

2  6 

3 

54  9 

6  9 

2  6 

9  12 

- 

4 

29, 

5 

2 

5 

52  12 

5  3 

- 

9 

- 

- 

30, 

1  6 

1  9 

2 

50  7 

4  13 

_ 

7  14 

_ 

_ 

May   1, 

1 

1  15 

1 

52  2 

4  15 

- 

8  8 

- 

- 

2, 

_ 

2  4 

_ 

52  5 

5  7 

_ 

9  8 

_ 

_ 

3, 

- 

1  15 

3 

57  5 

14  7 

- 

24  11 

- 

- 

4, 

1 

2  1 

11 

62  10 

6  15 

" 

42  13 

""" 

1  4 

68 


PHENOMENA  OF  PLANT-LIFE. 


Flow  of  Sap — Continued. 


DATE. 

I 

Betula  alba  var.  1 
populifolia. 

Juglans  cinerea.  1 

Betula  papyracea. 

Betula  lenta. 

Betula  lutea. 

Carpinus  Ameri-  1 
cana. 

Ostrya  Virginica.  1 

1  874. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz.  . 

Ibs.  oz. 

Ibs.  oz. 

Ibs.  oz. 

May  5, 

_ 

2  4 

7 

63  4 

5  15 

47  1 

_• 

6  2 

6,   , 

_ 

1   4 

_ 

57  13 

5  5 

43  14 

15 

9  10 

7,   . 

_ 

1   7 

3 

53  14 

5  8 

42  7 

4 

12  4 

8, 

_ 

.1  3 

_ 

49  1 

4  2 

39  8 

1 

11  3 

9,   . 

- 

1   4 

- 

46  7 

3  12 

37  8 

- 

9 

10,   . 

- 

2  3 

— 

50  6 

6  9 

43  2 

- 

15  5 

11, 

6 

1  8 

_ 

36  1 

8  8 

33  8 

4 

22  3 

12,   . 

6 

5 

- 

30  2 

12  5 

30  4 

5 

24  4 

13,   . 

3 

8 

- 

26  6 

11  14 

26  6 

1 

24  2 

14,   . 

6 

2 

- 

23  5 

4  10 

22  6 

- 

26  3 

15,   . 

12 

- 

- 

12  10 

2  15 

10  6 

- 

20  10 

16,   . 

2  5 

3 

- 

9  3 

1  15 

7  15 

1  4 

19  14 

17,   . 

2  6 

1  4 

— 

14  10 

13  13 

15  10 

1  9 

27  2 

18,   . 

2  1 

4 

1 

7  9 

4  9 

2  5 

1 

14  12 

19,   -.:; 

1  8 

- 

- 

3  14 

11  9 

8  11 

7 

14  13 

20,   . 

13 

1  13 

- 

2  2 

1  15 

2  5 

- 

3  1 

21,   . 

8 

- 

— 

7  1 

12 

12 

- 

1  14 

22,   . 

8 

12 

_ 

14 

'  6  2 

5  6 

1 

7  13 

23,   . 

4 

- 

- 

- 

- 

12 

— 

5 

24,   ; 

3 

- 

- 

- 

- 

- 

- 

- 

25,   . 

6 

- 

_ 

_ 

- 

_ 

- 

- 

26,   . 

10 

- 

- 

3 

11 

2  7 

- 

1  3 

27,   . 

8 

- 

- 

- 

- 

- 

- 

- 

28,   . 

1 

- 

- 

- 

- 

- 

- 

- 

29,   . 

1 

- 

- 

— 

- 

— 

- 

- 

30, 

2 

- 

- 

- 

- 

- 

- 

- 

81,   . 

1 

- 

- 

- 

- 

'- 

- 

- 

June  1, 

- 

- 

- 

- 

- 

- 

- 

- 

2,   . 

- 

- 

— 

- 

— 

- 

- 

- 

3,   . 

3 

I 

~ 

" 

" 

PHENOMENA  OF  PLANT-LIFE. 

Flow  of  Sap — Concluded. 


69 


DATB. 

Acer  sac- 

charinum. 

DATB. 

Acer  sac- 
charinum. 

DATE. 

Acer  sac- 
charinum. 

1873. 

Ibs.  oz. 

1874. 

Ibs.  oz. 

1874. 

Iba.  oz. 

Dec.  16, 

16      7 

Mar.    2, 

21  15 

Mar.  30,       . 

24 

17,       . 

— 

3,       . 

25     4 

31,       . 

6 

18,        . 

- 

4,       . 

8  13 

Apr.    1,       . 

5 

19, 

> 

5,       . 

11     8 

2,       . 

6 

20,        . 

8 

7,       . 

7     3 

,        18,       . 

36 

21, 

3 

8,       . 

23     3 

19,       . 

19 

22,        . 

10 

14,       . 

5  11 

20,       . 

- 

15,       . 

17     4 

21, 

12 

1874. 

16,       . 

29 

22,       . 

8 

Jan.     2, 

5    3 

17,       . 

23 

23,       . 

4 

3, 

8  10 

18,       . 

24  12 

24, 

3 

4, 

10    5 

19,       . 

16 

25,       . 

- 

7, 

— 

20,       . 

6     4 

26,       . 

11 

8,        . 

10     9 

21,       . 

48    4 

27,       . 

10     8 

9,        • 

10     1 

22,       . 

6  10 

28,       . 

_ 

10, 

2  10 

25, 

•12    8 

29,       . 

1  _ 

11,        • 

4 

27,       . 

24 

30,       . 

- 

23, 

'    — 

28,       . 

25 

24, 

2  15 

29,       . 

12 

TABLE 

Showing  the  variations  in  Water  Gauges  attached  to  roots  of  trees. 
The  figures  indicate  inches  of  water  in  tubes  of  such  size  that  a  column 
of  thirty-six  inches  weighs  one  ounce.  The  minus  sign  denotes  absorp- 
tion of  the  water  by  the  root,  and  the  absence  of  the  sign  denotes  flow  of 
sap  from  the  root.  The  size  of  the  trees  is  unimportant,  but  they  were 
all  vigorous  specimens,  standing  in  open  ground.  A  summary  of  the 
principal  facts  relating  to  the  four  species  which  showed  the  greatest 
fluctuations  is  given  below. 

Acer  saccharinum. — Water  gauge  attached,  May  1.  Maximum  absorption  was  69 
inches  or  1.91  ounces  of  water,  May  10.  Minimum,  2  inches  or  0.055  of  an  ounce, 
June  1.  Total  absorption,  in  the  month  of  May,  410.7  inches  or  11.4  ounces.  No 
flow  of  sap. 

Quercus  alba.— Gauge,  attached,  April  11.  Maximum  absorption,  46  inches  or  1.28 
ounces,  May  2.  The  tube,  however,  was  often  emptied  of  its  contents  within  an  hour 
or  two  after  it  was  filled.  Maximum  flow,  2.5  inches  or  0.07  of  an  ounce,  May  26. 
Total  absorption,  759.1  inches  or  21.09  ounces.  Total  flow,  3.5  inches  or  0.097  of  an 
ounce. 

Ulmus  Americana.— Gauge  attached,  April  11.  Maximum  absorption,  26.5  inches 
or  0.74  of  an  ounce,  April  15.  Maximum  flow,  12.5  inches  or  0.34  of  an  ounce,  April 
29.  Total  absorption,  155  inches  or  4.30  ounces.  Total  flow,  256.8  inches  or  7.13 
ounces. 

Pyrus  Mahis.— Gauge  attached,  April  11.    Maximum  absorption,  25.0  inches  or  0.70 
of  an  ounce,  April  16.    Maximum  flow,  22  inches  or  0.60  of  an  ounce,  May  16.    Total 
absorption,  175.3  inches  or  4.85  ounces.    Total  flow,  290.7  inches  or  8.07  ounces. 
10 


70 


PHENOMENA  OF  PLANT-LIFE. 

Water  Gauges. 


DATS. 

Acer  sacchnrl- 
num,  detached 
root. 

Pyrus  Mains,  de- 
tached root. 

Castanca  vesca, 
detached  root. 

Ulmus  America- 
na, detached 
root. 

Quercul  alba, 
detached  root. 

Fraxlnus  Amer-  J 
icana,  detach'  d  j 
root. 

1874. 

Apr.  11%      . 

_ 

—19.0 

—7.5 

—9.0 

—45.0 

—1.0 

12,      .        . 

- 

—13.0 

—2.0 

—8.0 

—15.0 

- 

13,      .        . 

- 

—7.5 

—2.0 

—9.0 

—15.0 

—3.0 

14,      . 

_ 

—8.5 

—3.0 

—11.5 

—45.0 

—2.0 

15,      .        . 

- 

—21.0 

—8.0 

—26.5 

—29.5 

—5.0 

16,      . 

_ 

—25.0 

—6.0 

—25.5 

—300 

—4.0 

17,      .        . 

- 

- 

—60 

—25.5 

—30.0 

—2.0 

18,      . 

_ 

- 

—3.0 

—18.5 

—30.0 

—1.0 

19,      . 

— 

- 

--5.5 

—16.0 

—30.0 

—1.5 

20,      .        . 

- 

- 

—3.5 

—5.5 

—30.0 

—1.5 

21,      . 

_ 

_ 

—2.5 

0.3 

—31.0 

—05 

22,      .        ,,- 

- 

—16.0 

—1.0 

1.3 

—31.0 

—0.5 

23,      .      V 

- 

—15.5 

-0.3 

2.0 

—31.0 

—1.0 

24,      . 

_ 

—11.0 

- 

1.8 

— 

- 

25,      .       .. 

— 

—9.5 

—2.0 

3.5 

—32.0 

—1.0 

26,      .        . 

- 

—5.5 

—2.0 

1.3 

—31.0 

—1.0 

27,      . 

_ 

—4.5 

— 

5.0 

—12.0 

— 

28,      .        . 

_ 

—12.0 

- 

6.5 

—28.0 

—0.8 

29,      . 

— 

—2.3 

- 

12.5 

—32.0 

—0.5 

30,      . 

_ 

—3.0 

—0.5 

10.0 

—30.0 

—0.8 

May    1,      .        . 

- 

- 

—0.3 

8.0 

—25.5 

—0.3 

2,      .        . 

—14.2 

—0.8 

—1.5 

7.5 

—46.0 

—0.5 

3,      .        . 

—17.5 

—0.7 

0.5 

6.0 

—20.0 

—  0.6 

—24.0 

—0.7 

—2.0 

65 

—15.5 

—1.0 

5,      /I 

—26.0 

—0.3 

—2.3 

4.5 

—17.0 

—1.0 

—40.0 

_ 

—3.0 

10.0 

—14.0 

—1.0 

?!      •" 

—38.0 

0.3 

—2.0 

4.5 

—12.0 

—1.3 

8,      .  ,     . 

—35.0 

—0.5 

—2.0 

1.8 

—  10.0 

—  t.O 

9,      .        . 

—32.0 

0.3 

—1.0 

4.0 

—7.0 

—1.0 

10,      . 

—69.0  : 

0.8 

—1.0 

1.7 

—1.0 

—0.7 

11,      .     '  .  < 

—36.0  ' 

4.0 

—1.3 

3.5 

—2.0 

—1.3 

12,      . 

—19.0 

3.5 

—1.3 

1.0 

—3.0 

—1.0 

13,      . 

—21.0 

3.0 

—0.5 

2.0 

—1.0 

—1.0 

U,      ,        . 

—21.0 

6.5 

—1.0 

2.5 

—2.0 

—1.0 

15,      .        » 

—16.0 

10.5 

—1,0 

2.3 

—4.0 

—1.3 

16,      .        .  j 

—9.0 

22.0 

— 

3.0 

—3.0 

—1.0 

17,      . 

—30 

11.5 

—05 

4.0 

- 

—0.5 

18,      . 

—4.0 

16.5 

—0.5 

4.0 

—15 

—0.5 

19,      .        . 

—10.0 

13.0 

_ 

4.0 

—1.0 

—1.0 

20,      . 

—9.0 

9.0 

—0.5 

4.0 

—1.8 

—0.6 

21,      . 

—70 

6.0 

—0.5 

40 

—1.0 

—0.6 

52,      . 

—2.0 

5.5 

_ 

4.0 

0.5 

—0.3 

23,      . 

—5.0 

5.0 

—0.8 

3.0 

0.5 

—0.5 

24,      . 

—3.0 

4.0 

--0.6 

3.0 

1.0 

—0.5 

25,      .        »| 

—5.0 

4.0 

—0.3 

8.5 

—1.0 

—0.6 

26,      .        ,  ; 

—2.0 

8.5 

0.5 

5,0 

2.5 

—0.5 

27,      . 

—7.0 

5.0 

—0.5 

3.0 

—1.0 

—1.0 

28,      .        . 

—7.0 

5.0 

_ 

4.0 

—1.0 

—1.0 

29,      .        . 

—6.0 

6.5 

—0.5 

4.0 

—0.5 

—2.0 

PHENOMENA  OF  PLANT-LIFE. 

Variation  in  Water  Gauges — Concluded. 


71 


DATE. 

"C   "« 

eS     3 

ps 

Pyrus  Mains,  de- 
tached root. 

Castanea  vesca, 
detacbed  root. 

TJlmos  America- 
na, detached 
root. 

Quereua  alba, 
detached  root. 

Fraxinns  Amer- 
icana, detach'd 
root. 

1S74. 

May  80,      . 

—6.0 

6.5 

—0.3 

4.0 

—1.5 

—2.0 

31,      .        . 

—5.0 

7.0 

—03 

6.0 

—1.5 

—1.5 

June    1, 

—2.0 

7.0 

—0.3 

5.0 

—0.5 

—1.0 

2,      .        . 

—5.0 

8.0 

—0.5 

4.0 

—1.3 

—1.3 

3,      . 

—3.0 

14.0 

—0.3 

4.0 

—1.0 

—1.3 

4,      . 

_ 

8.0 

- 

4.0 

—2.0 

—1.0 

5,      .        . 

- 

90 

- 

4.0 

—1.0 

—1.0 

6,      .        . 

- 

8.3 

— 

3.5 

M 

- 

7,      .        . 

- 

120 

- 

4.0 

- 

- 

8,      . 

_ 

11.5 

- 

3.5 

— 

_ 

9,      .        . 

- 

12.0 

- 

3.0 

- 

— 

10,      .        . 

- 

11.0 

- 

3.5 

- 

- 

11,      .        . 

- 

10.5 

- 

3.0 

_ 

. 

12,      .        . 

- 

8.5 

- 

4.0 

- 

- 

13,      .        . 

_ 

6.5 

- 

2.5 

_ 

„ 

14,      .        . 

- 

6.0 

- 

2.0 

- 

» 

15,      . 

_ 

5.0 

- 

3.0 

MP 

~ 

16,      .        . 

- 

5.5 

— 

2.0 

_ 

- 

17,      . 

_ 

5.0 

_ 

2.0 

• 

... 

18,      . 

_ 

6.0 

- 

5.0 

- 

. 

19,      .        . 

- 

5.0 

- 

2.0 

- 

— 

20,      . 

- 

4.0 

_ 

2.5 

_ 

*, 

21,      .        . 

- 

6.0 

- 

1.5 

-         ' 

• 

22,      . 

_ 

1.5 

- 

1.5 

_ 

_ 

23,      .        . 

- 

4.0 

- 

1.3 

- 

- 

24,      .        . 

- 

4.5 

— 

4.5 

— 

_ 

25,      .        . 

- 

2.0 

- 

1.5 

- 

- 

26,      . 

— 

1.5 

— 

2.0 

_ 

w 

27,      . 

_ 

3.0 

_ 

2.0 

_ 

_ 

28,      . 

«. 

1.0 

_ 

1.5 

_ 

— 

29,      . 

__ 

0.5 

— 

1.0 

_ 

__ 

30,      .        . 

•~ 

1.0 

— 

2.0 

— 

— 

72 


PHENOMENA  OF  PLANT-LIFE. 


TABLE 

Showing  the  fluctuations  in  Mercurial  Gauges  attached  to  the  roots 
and  trunks  of  trees,  with  descriptions  of  the  specimens  under  observa- 
tion. The  figures  denote  inches  of  mercury,  and  when  the  minus  sign  is 
prefixed  tney  indicate  suction ;  otherwise,  pressure.  To  convert  inches  of 
mercury  into  feet  of  water,  multiply  the  number  by  13.60,  the  specific 
gravity  of  mercury,  and  divide  the  product  by  12.  When  the  figures  are 
omitted  for  one  or  more  days  after  the  record  has  begun,  it  shows  that 
in  consequence  of  some  accident  no  observation  could  be  made.  The 
hour  for  the  first  observation  of  any  day  is  seven  A.M.,  that  for  the  second, 
is  noon,  and  that  for  the  third,  is  six  P.  M. 


NAME. 

Height, 
feet. 

Girth, 
feet,  in. 

Acer  rubrum. 
A.  saccharinum. 
Betula  alba  var.  p< 

jpulifolia.  ...... 

40 

60 
30 

2      6 

6    4 
1    4 

B.  alba  var.  popub 
B.  lenta,  root. 
B.  lutea.  .       f. 
B.  papyracea. 
Ostrya  Virginica. 
Pyrus  Malus,  root. 
Vitis  aestivalis. 
V.  aestivalis,  root. 

folia,  root  

35 
65 
60 
60 
45 
35 
50 
40 

1     8 
3  10 
3    8 
3    9 
2  10 
2    9 
1    0 
10 

Mercurial  Gauges. 


DATE. 

if! 

ll 

Is  *• 

ft 

j| 

.    «  "S 
,3    o 
"3    M 

!          1"     *    i 

Ill 

«    £ 

I1 

|l 

1    1 

if 

W        ** 

> 

PH 

1874—  Apr.  12,  . 

8.6 

_ 

_           4 

_ 

_ 

18,  .        .        . 

22.5 

- 

- 

— 

- 

21,  . 

25.2 

- 

— 

— 

— 

22,  .        .         . 

26.0 

- 

- 

- 

- 

23,  . 

26.4 

— 

— 

— 

_ 

24,  .        .        . 

27.0 

- 

- 

- 

- 

25,  .         .        . 

28.3 

— 

- 

— 

- 

26,  .         .        . 

27.3 

- 

- 

- 

- 

27,  .         .        . 

28.0 

- 

— 

- 

— 

28,  . 

28.3 

_ 

— 

_ 

_ 

29,  .         .        . 

27.3 

- 

- 

— 

- 

30,  .        .        . 

28.3 

- 

- 

- 

- 

May    1,  .        .        . 

27.8 

- 

- 

- 

- 

2,  . 

28.2 

•~ 

" 

—4.0 

PHENOMENA  OF  PLANT-LIFE. 


73 


Fluctuations  in  Mercurial  Gauges — Continued. 


DATE. 

Betula  alba  var. 
populifolia,  de- 
tached root. 

Vitis  sestivalis, 
lower  gauge. 

Vitis  aestiralis, 
upper  gauge. 

Vitf»  aeitivalis, 
detached  root. 

Pyrus  Malus,  de-  1 
tached  root. 

1874—  May    3,  . 

30.0 



_ 

—3.7 

_ 

4,  . 

30.0 

— 

— 

—3.3 

— 

5,  . 

31.0 

- 

- 

—3.3 

- 

6,  .        .         . 

31.0 

— 

— 

—2.9 

— 

7,  . 

31.0 

9.8 

_ 

—2.1 

'  - 

8,  .         .         . 

31.0 

12.4 

- 

—2.0 

- 

9,  .         .        . 

31.5 

9.0 

- 

—1.3 

- 

10,  .        .        . 

28.5 

14.0 

- 

—0.2 

_ 

11,  . 

315 

30.2 

- 

3.1 

- 

12,  . 

33.6 

30.1 

3.0 

4.5 

_ 

13,  .         .        . 

32.0 

29.2 

0.7 

2.2 

- 

14,  . 

31.0 

39.2 

10.2 

8.6 

_ 

15,  . 

24.6 

59.0 

30.0 

22.6 

—1.4 

16,  .         .        . 

25.0 

58.0 

35.0 

17.4 

2.5 

17,  .        .         . 

26.9 

50.0 

30.0 

8.8 

4.8 

_ 

52.5 

29.0 

10.5 

6.5 

18,  .         .        . 

16.8 

450 

24.3 

15.0 

6.7 

19,  .        .        . 

17.0 

45.0 

22.3 

10.7 

3.9 

20,  . 

9.0 

40.0 

20.0 

8.4 

3.2 

21,  .        .         . 

6.7 

39.2 

18.0 

118 

5.7 

22,  .        .         . 

- 

410 

16.3 

10.7 

57 

23,  . 

0.4 

35.7 

15.7 

11.1 

5.2 

—3.0 

40.0 

15.3 

18.2 

6.0 

24,  .         .        . 

—  2.0 

45.4 

14.4 

19.5 

6.0 

_ 

51.0 

15.0 

23.0 

_ 

_ 

539 

15.0 

_ 

_ 

25,  .         .        . 

—08 

62.7 

14.4 

40.0 

6.6 

26,  . 

2.5 

74.0 

20.7 

52.5 

7.2 

27,  . 

—3.0 

66.0 

23.5 

429 

_ 

_ 

57.0 

23.3 

48.0 

8.4 

28,  .        .        . 

—5.3 

49.2 

233 

47.0 

7.0 

_ 

54.0 

22.0 

65.0 

_ 

29,  .        .         . 

—5.4 

57.3 

22.2 

60.5 

7.2 

- 

62.0 

238 

78.3 

_ 

30,  . 

—5.0 

59.8 

24.5 

66.5 

90 

- 

_ 

_ 

78.0 

125 

_ 

_ 

_ 

72.0 

6.2 

31,  .        .        . 

—4.3 

44.5 

17.5 

57.5 

100 

_ 

50.2 

18.6 

63.0 

133 

_ 

47.3 

18.0 

71.0 

10.5 

June  1,  . 

—3.0 

48.0 

17.0 

54.3 

9.0 

_ 

40.0 

16.0 

52.2 

7.4 

2,  . 

—5.0 

34.0 

15.0 

370 

6.2 

_ 

21.5 

13.3 

43.9 

7.4 

3,  . 

_ 

23.6 

12.5 

37.6 

5.1 

_ 

19.5 

11.3 

42.1 

7.1 

4,  . 

—4.8 

25.1 

10.8 

41.0 

5.8 

- 

.8 

10.3 

- 

_ 

5,  . 

- 

25.6 

9.4 

39.2 

4.9 

- 

23.8 

9.1 

43.6 

7.0 

74 


PHENOMENA  OF  PLANT-LIFE. 


Fluctuations  in  Mercurial  Gauges — Continued. 


DATE. 

Betula  alba  var. 
populifolia,  de- 
tached root. 

Vitis  ,-estivalis, 
lower  gauge. 

Vitis  asstivalis, 
upper  gauge. 

Vitis  sestivalis, 
detached  root. 

Pyrus  Malus,  de- 
tached root. 

1874—  June  6,  .        .        . 

_ 

27.0 

85 

41.8 

4.3 

_ 

26.8 

7.9 

48.0 

5.7 

7,  .    '    .        . 

—6.0 

30.0 

7.5 

42.0 

4.8 

- 

17.9 

6.6 

43.0 

6.5 

_ 

_ 

_ 

44.8 

5.6 

8,  .        .        . 

- 

33.9 

6.7 

42.4 

4.5 

- 

6.9 

44 

41.4 

6.8 

_ 

_ 

_ 

42.7 

5.8 

9,  .        .        . 

- 

10.0 

3.5 

35.8 

3.8 

_ 

2.7 

2.8 

41.4 

6.8 

10,  .        .        . 

—10.0 

6.0 

2.0 

37.0 

4.1 

_ 

_ 

_ 

38.3 

7.3 

_ 

_ 

_ 

42.0 

73 

11,  . 

—11.5 

3.2 

—0.3 

34.2 

4.0 

_ 

_ 

_ 

33.3 

6.6 

_ 

_ 

_ 

322 

6.3 

12,  .        .        . 

—9.2 

11.8 

1.1 

315 

4.1 

_ 

_ 

_ 

325 

6.0 

__ 

_ 

_ 

32.9 

6.0 

18,  .        .        . 

—10.8 

0.2 

—5.4 

31.0 

3.4 

14,  .        .        . 

—11.2 

—4.0 

—3.3 

30.2 

3.5 

15,  . 

—12.7 

—8.0 

—4.5 

28.0 

2.7 

_ 

—0.3 

—5.0 

35.0 

5.8 

16,  .        .        . 

—  13.0 

;    1.1 

—6.0 

34.6 

2.8 

_ 

—6.2 

—6.6 

38.6 

4.5 

17,  .        .        . 

—12.0 

38 

—7.1 

38.0 

4.5 

18,  . 

—11.7 

—3.4 

—7.9 

34.3 

3.4 

19,  .        .        . 

—12.4 

—8.7 

—9.0 

30.3 

3.0 

20,  . 

—12.7 

—6.3 

—9.5 

27.5 

2.8 

21,  .        .        . 

—12.4 

—8.7 

—9.3 

31.5 

2.0 

_ 

_ 

_ 

35.6 

2.5 

22,  . 

—12.2 

—11.0 

—9.1 

343 

1.3 

_ 

_ 

_ 

38.2 

2.0 

23,  . 

—13.5 

—11.0 

—9.3 

38.5 

2.0 

24,  . 

—13.7 

—10.6 

—9.5 

39.0 

2.6 

25,  . 

—14.2 

—117 

—9.0 

34.3 

2.2 

26,  . 

—146 

—8.5 

—9.0 

33.0 

2.0 

27,  . 

—13.6 

—8.7 

—8.3 

39.0 

3.0 

28,  . 

—14.3 

—11.3 

—7.9 

38.5 

1.8 

29,  .        .        . 

—14.4 

—12.7 

—7.0 

37.3 

2.0 

30,  .        .        . 

—14.6 

—110 

—7.5 

39.0 

0.8 

July    1,  .        .       . 

—15.0 

- 

- 

37.6 

- 

2,  ... 

—15.5 

_ 

- 

38.5 

— 

*           8,  • 

—15.5 

_ 

- 

41.0 

- 

—16.0 

_ 

_ 

40.0 

_ 

5',  !     ! 

—15.8 

_ 

_ 

35.3 

_ 

6,  . 

-16.1 

—8.6 

—5.3 

33.3 

- 

7,  . 

—16.2 

_ 

_ 

34.3 

_ 

8,  .        .        . 

—16.3 

— 

_ 

36.0 

_ 

9,  .        .        . 

—16.4 

- 

- 

40.4 

— 

PHENOMENA  OF  PLANT-LIFE. 


75 


Fluctuations  in  Mercurial  Gauges — Concluded. 


DATE. 

Betula  alba  var. 
populifolia,  de- 
tached root. 

Vitta  wstivalis, 
lower  gauge. 

Vitis  testivalls, 
upper  gauge. 

Vitis  asstlvalls, 
detached  root. 

Pyrua  Malui,  de- 
tached root. 

1874—  July  10,  . 
12,  . 

—16.5 

—15.8 

- 

- 

44.0 
37.5 

- 

13,  . 

—15.0 

« 

- 

32.7 

- 

14,  . 

—16.6 

- 

- 

33.5 

- 

15,  . 

—16.4 

- 

- 

37.4 

- 

16,  .        .        . 

—15.8 

- 

- 

42.0 

- 

17,  . 

—16.6 

MI 

- 

43.0 

- 

18,  . 

'  —16.6 

-. 

- 

40.4 

- 

19,  .        .        . 

—16.7 

—6.5 

—5.0 

41.6 

- 

20,  . 

—16.7 

- 

— 

42.2 

- 

21,  .        .        . 

—16.5 

- 

- 

41.0 

- 

22,  . 

—16.6 

- 

— 

36.0 

— 

23,  . 

—16.6 

—6.7 

—4.4 

34.0 

- 

24,  . 

—16.8 

_ 

- 

38.5 

- 

25,  . 

—16.8 

- 

- 

39.7 

- 

26,  .         .         . 

—17.0 

—6.8 

—5.0 

42.0 

- 

27,  . 

—17.0 

— 

— 

37.9 

- 

28,  .        .        . 

—17.4 

- 

- 

36.5 

- 

29,  . 

—17.4 

- 

- 

354 

fif*  -  i_i.~ 

30,  .        .        . 

—17.2 

- 

- 

35.6 

I   <-/-!  n, 

31,  . 

—17.9 

_ 

— 

28.4 

\  *^~* 

Aug.  1,  . 

—17.9 

- 

- 

28.9 

t     - 

3,  .        .        . 

—18.4 

— 

_ 

33.4 

Yy-f, 

4,  . 

—19.4 

- 

_ 

29.9 

\£'\ 

5,  .        .        . 

—19.4 

—3.0 

—5.0 

29.0 

X*^ 

6,  . 

—18.5 

- 

- 

27.1 

— 

7,  .        .        . 

—19.0 

- 

•  - 

28.7 

- 

8,  .        .        . 

—18.8 

- 

- 

31.5 

- 

9,.        .        . 

—18.5 

— 

— 

31.4 

— 

10,  .        .        . 

—18.2 

- 

- 

31.0 

- 

11,  . 

—18.3 

- 

- 

27.2 

- 

12,  .        .         . 

—18.3 

- 

- 

28.9 

- 

13,  . 

—18.3 

- 

- 

26.0 

- 

14,  . 

—18.8 

- 

- 

24.1 

- 

15,  .        .         . 

—18.9 

- 

- 

23.6 

- 

16,  .         .        . 

—18.8 

— 

- 

28.2 

- 

17,  .         .        . 

—19.2 

—3.5 

—6.3 

25.3 

18,  . 

—19.2 

- 

- 

26.0 

- 

19,  . 

—19.3 

— 

_ 

26.0 

_ 

20,  . 

—19.4 

- 

- 

21.2 

- 

21,  .        .         . 

—19.3 

- 

- 

23.2 

- 

22,  . 

—193 

- 

- 

27.7 

— 

23,  .        .        . 

—19.6 

- 

- 

18.8 

- 

25,  .        .         . 

—19.8 

.-. 

_ 

17.9 

- 

26,  .        .         . 

—20.2 

- 

- 

18.4 

- 

27,  .        .        . 

—19.4 

— 

— 

21.1 

— 

29,  . 

—19.4 

- 

- 

20.6 

- 

30,  .        .        . 

—19.0 

— 

_ 

22.4 

_ 

31,  . 

—19.0 

_ 

__ 

20.8 

— 

Sept.  14,  . 

- 

- 

- 

17.0 

- 

^ 


':-vi 


76 


PHENOMENA  OF  PLANT-LIFE. 

Fluctuations  in  Mercurial  Gauges. 


DATE. 

Betula  lutea, 
lower  gauge. 

Betula  lutea, 
upper  gauge. 

Betula  lenta,  de- 
tached root. 

Betula  alba  var. 
populifolia. 

OstryaVirginica. 

1874—  Apr.    9,  . 

14.2 

_ 

_ 

9.5 

_ 

16.5 

_ 

_ 

11.5 

1.5 

17.0 

- 

_ 

11.4 

0.9 

10,  .        .        . 

18.5 

- 

- 

13.2 

1.6 

21.0 

_ 

_ 

14.7 

3.5 

20.6 

- 

- 

13.7 

0.5 

11,  .      :     . 

22.2 

- 

- 

15.4 

3.8 

22.5 

_ 

— 

14.0 

0.6 

21.2 

_ 

- 

0.3 

—2.7 

12,  .        .        . 

30.0 

- 

- 

- 

5.0 

29.6 

- 

— 

0.3 

5.2 

—0.1 

- 

- 

0.2 

—2.0 

13,  .        .        . 

11.6 

- 

•   - 

2.2 

1.6 

—1.6 

- 

- 

0.2 

—1.5 

—5.7 

- 

- 

—2.2 

—1.4 

14,  .        .        . 

9/9 

- 

- 

4.0 

1.3 

11.0 

— 

— 

1.2 

1.5 

11.5 

- 

- 

0.3 

1.5 

15,  .        .        . 

22.6 

- 

- 

0.5 

2.6 

27.0 

- 

- 

10.2 

6.0 

27.0 

_ 

- 

10.5 

6.3 

16,  .        .        . 

27,7 

- 

- 

11.8 

7.2 

32.0 

- 

- 

15.5 

10.5 

31.6 

— 

_ 

11.4 

10.2 

17,  .        .        . 

34.0 

- 

- 

14.8 

11.4 

35.5 

- 

_ 

146 

10.4 

36.1 

- 

- 

_ 

9.6 

18,  .        .        . 

50.5 

.  - 

- 

29.0 

16.5 

29.0 

_ 

_ 

29.6 

3.0 

34.4 

- 

- 

27.0 

0.7 

19,  .        .        . 

380 

- 

- 

10.3 

4.8 

47.0 

- 

_ 

_ 

11.5 

45.0 

- 

- 

_ 

7.5 

20,  .        .        . 

49.0 

- 

- 

-    - 

8.2 

53.0 

- 

- 

_ 

93 

53.6 

_ 

_ 

- 

9.0 

21,  .        .        . 

57.6 

- 

- 

- 

8.9 

63.0 

_ 

— 

- 

11.0 

52.2 

_ 

_ 

180 

5.0 

22,  .        .        . 

29.6 

•  - 

- 

10.3 

2.5 

65.5 

- 

- 

32.8 

10.0 

_ 

- 

_ 

26.0 

7.3 

23,  .        .         . 

'_ 

- 

_ 

24.4 

5.4 

53.0 

_ 

23.6 

35.0 

6.2 

526 

_ 

26.0 

33.6 

2.0 

24,  .        .        . 

350 

5.0 

63.0 

20.8 

3.4 

65.0 

36.8 

58.0 

28.8 

8.2 

52.6 

19.8 

52.0 

250 

5.8 

25,  .        .         . 

48.8 

22.0 

51.4 

32.2 

3.3 

52.0 

22.0 

430 

22.7 

0.2 

PHENOMENA  OF  PLANT-LIFE. 


77 


Fluctuations  in  Mercurial  Gauges — Continued. 


DATE. 

Betula  lutea, 
lower  gauge. 

Betula  lutea, 
upper  gauge. 

Betula  lenta,  de- 
tached root. 

Betula  alba  var. 
populifolia. 

Ostrya  Virglnica. 

1874—  Apr.  25,  . 
26,  .        .        . 

43.0 

15.5 

30.0 
4.4 

20.0 
—0.6 

—3.3 

2.2 

36.0 

11.6 

33.8 

23.4 

1.5 

33.0 

8.7 

33.0 

15.4 

—6.7 

27,  . 

45.7 

20.1 

35.3 

25.5 

1.7 

58.0 

34.2 

37.6 

24.3 

7.0 

42.5 

15.7 

33.4 

9.8 

—6.7 

28,  . 

46.3 

—9.3 

7.3 

3.7 

_ 

36.6 

12.3 

19.2 

—0.2 

2.8 

26.0 

3.2 

20.0 

2.2 

—3.8 

29,  .        .        . 

37.3 

13.5 

23.6 

- 

—0.2 

43.5 

19.0 

26.6 

_ 

2.3 

44.8 

20.0 

30.0 

_ 

1.6 

30,  .        .        . 

41.6 

17.7 

- 

7.3 

2.6 

47.6 

22.0 

_ 

17.5 

3.2 

500 

23.0 

_ 

6.8 

5.0 

May    1,  .        .        . 

42.6 

16.5 

- 

- 

0.2 

56.0 

28.3 

44.1 

4.8 

6.3 

54.0 

26.6 

46.0 

8.5 

6.2 

2,  . 

42.0 

15.0 

55.5 

6.5 

0.4 

_ 

0.8 

37.0 

14.1 

4.8 

_ 

0.8 

29.0 

8.8 

4.0 

3,  .        .        . 

_ 

—5.5 

32.0 

—1.5 

3.5 

_ 

18.5 

40.0 

30.0 

11.0 

_ 

8.0 

52.6 

6.0 

10.7 

4,  . 

- 

0.5 

45.5 

—1.4 

10.0 

62.3 

35.0 

41.5 

345 

15.0 

38.6 

13.0 

52.4 

13.2 

15.1 

5,  .        .        . 

32.0 

10.3 

52.5 

2.0 

13.0 

54.0 

29.4 

51.2 

27 

16.6 

38.5 

11.5 

54.0 

12.0 

14.0 

6,  .        ".         . 

140 

- 

50.7 

0.6 

10.2 

52.8 

25.5 

557 

1.5 

22.4 

27.0 

0.2 

615 

12 

20.8 

7,  .        .         . 

4.3 

t-1.0 

56.6 

—4.1 

22.5 

45.0 

198 

53.2 

23.2 

25.2 

36.2 

11.0 

57.3 

10.4 

25.2 

8,  . 

11.3 

0.2 

55.2 

—0.6 

23.6 

51.9 

25.9 

56.1 

18.6 

28.5 

31.2 

44 

59.2 

7.4 

22.1 

9,  .        .        . 

6.4 

— 

59.1 

—6.4 

21.7 

63.2 

36.4 

60.3 

32.0 

31.6 

40.0 

5.6 

62.1 

12.0 

29.0 

10,  . 

26.0. 

3.7 

64.5 

—4.9 

33.4 

40.0 

28 

66.0 

10.7 

24.1 

2.6 

_ 

68.0 

—15.0 

10.2 

11.  . 

6.6 

1.0 

56.0 

—17.0 

10.3 

39.0 

20.0 

56.9 

7.4 

10.5 

7.4 

9.5 

15.0 

0.8 

_ 

12,  . 

—1.6 

8.1 

61.0 

101 

- 

11 


78 


PHENOMENA  OF  PLANT-LIFE. 


Fluctuations  in  Mercurial  Gauges — Continued. 


DATE. 

Betula  lutea, 
lower  gauge. 

Betula  lutea, 
upper  gauge. 

Betula  lenta,  de- 
tached root. 

Betula  alba  var. 

populifolia. 

OstryaVirginlca. 

1874—  May  12,  .        .        . 

11.0 

—4.1 

53.0 

17.2 

6.8 

—4.8 

—3.6 

54.6 

—  02 

29.6 

13,  .      ;  .        . 

—3.5 

/—  3.7 

56.0 

2.3 

35.6 

- 

- 

_ 

_ 

—3.0 

5.6 

—9.8 

61.0 

- 

23.9 

14,  .      •  .        . 

4.6 

—2.9 

58.0 

—9.1 

284 

23.0 

—0.8 

59.0 

3.7 

21.4 

—11.2 

—2.6 

58.7 

—2.6 

8.0 

15,  .        .         . 

—13.1 

—2.6 

52.5 

—11.0 

15.7 

15.4 

—2.3 

54.1 

—2.0 

16.2 

—10.7 

—2.4 

53.0 

—85 

—3.6 

16,  .        .        . 

7.8 

—2.4 

42.2 

—0.3 

9.0 

5.2 

—2.0 

44.2 

4.3 

—2.7 

—19.8 

—2.0 

43.0 

—6.0 

—17.1 

17,  . 

—14.3 

—2.1 

38.0 

—10.1 

—105 

9.8 

—2.1 

37.0 

—57 

7.7 

10.0 

—2.1 

36.9 

—4.4 

7.9 

18,  .        .        . 

2.7 

—2.1 

33.2 

—4.0 

—8.0 

3.0 

—2.8 

32.4 

—2.7 

—6.3 

19,  .        .        . 

—2.7 

—2.1 

33.2 

—4.0 

—8.0 

—18.5 

—2.2 

32.8 

—6.3 

—21.7 

20,  .        .        . 

—15.6 

—2.2 

29.4 

—8.5 

—16.0 

13.4 

—2.1 

32.2 

—6.0 

15.1 

16.3 

—2.0 

32.0 

—10.1 

13.0 

21,  .        .        . 

—14.7 

—2.1 

30.2 

—12.0 

—9.3 

1.0 

—2.2 

30.6 

—10.0 

—6.0 

—1.6 

—2.1 

30.5 

—9.8 

—5.3 

22,  . 

6.0 

- 

28.0 

—8.4 

—3.2 

—9.0 

- 

28.8 

—7.3 

—6.0 

—14.0 

- 

284 

—10.6 

—9.4 

23,  . 

—14.0 

_ 

25.0 

—12.0 

—7.1 

—14.2 

- 

28.3 

—12.0 

—58 

—14.5 

_ 

28.3 

—10.0 

—5.0 

24,  . 

—13.8 

_ 

25.2 

—15.0 

5.0 

-12.t 

- 

29.5 

—14.0 

5.0 

—12.3 

_ 

28.8 

—14.0 

48 

25,  .        .        . 

—79 

- 

27.8 

—14.0 

—5.3 

—5.0 

_ 

28.0 

—13.0 

40 

—2.9 

_ 

28.0 

—11.9 

—3^0 

26   .         . 

—1.0 

- 

25.5 

—11.4 

2.0 

—7.0 

_ 

26.0 

—11.7 

—7.6 

—9.3 

- 

25.0 

—10.4 

6.3 

27    .        . 

—9.6 

_. 

22.0 

—11.1 

—5.5 

—8.3 

_ 

25.4 

—8.6 

—4.9 

—7.0 

_ 

26.0 

—8.5 

—5.0 

28,  . 

—7.4 

_ 

22.6 

—9.6 

—5.0 

—6.0 

- 

25.9 

—6.6 

—4.4 

—6.0 

_ 

25.6 

—6.8 

—5.0 

29,  .        .        . 

—5.5 

- 

22.6 

—5.5 

—4.8 

—5.3 

— 

25.0 

—4.0 

—4.3 

PHENOMENA  OF  PLANT-LIFE. 


79 


Fluctuations  in  Mercurial  (gauges — Concluded. 


DATE. 

Betula  lutea, 
lower  gauge. 

Betula  lutea, 
upper  gauge. 

Betula  lenta,  de- 
tached root. 

Betula  alba,  var. 
populifolia. 

Ostiya  Virginica. 

1874—  May  29,  . 

—5.3 

_ 

27.7 

—4.9 

—5.0 

30,  .        .        . 

—5.0 

- 

22.0 

—6.0 

—4.8 

—3.2 

_ 

26.0 

—4.0 

—4.4 

—3.0 

- 

25.5 

—4.4 

—4.6 

31,  .        .        . 

—2.3 

- 

21.4 

—5.3 

—4.5 

—1.8 

_ 

23.2 

—4.4 

—4.8 

June,  1,  . 

—1.9 

- 

20.0 

—5.0 

—4.5 

—1.5 

_ 

21.0 

—2.6 

—5.0 

—2.0 

_ 

20.4 

—3.0 

—4.8 

2,  .         .        . 

—2.5 

- 

18.0 

—5.2 

—  4.7 

—1.2 

_ 

16.4 

—4.7 

—4.6 

3,  ... 

—1.2 

- 

16.4 

—4.7 

—4.6 

4,  . 

—2.1 

_ 

17.3 

—5.2 

—4.6 

5,  . 

—2.2 

_ 

17.0 

—1.7 

—4.6 

6,  .        .         . 

—2.0 

- 

17.0 

—3.0 

—4.6 

7,  .        .        . 

1.4 

_ 

16.7 

—3.4 

- 

8,  .        .        . 

1.5 

_ 

17.0 

—2.4 

- 

9,  . 

—0.4 

_ 

14.7 

—4.6 

_ 

10,  .        .        . 

- 

- 

14.2 

—3.0 

- 

11,  . 

0.3 

_ 

10.0 

—4.0 

_ 

12,  .        .        . 

0.3 

- 

10.0 

—3.6 

- 

13,  . 

0.1 

- 

5.0 

—3.7 

— 

14,  . 

—0.3 

_ 

9.0 

—4.0 

_ 

15,  .         .        . 

—0.4 

_ 

10.0 

—4.0 

- 

16,  . 

0.4 

- 

11.5 

—3.4 

_ 

17,  .        .        . 

1.0 

- 

12.0 

—3.0 

- 

18,  . 

1.8 

_ 

14.3 

—3.0 

_ 

19,  .        .        . 

1.0 

- 

12.6 

—3.2 

- 

20,  . 

1.4 

_ 

120 

_ 

_ 

22,  . 

0.7 

_ 

12.0 

_ 

_ 

23,  .         .         . 

1.0 

_ 

12.4 

_ 

- 

24,  . 

1.3 

_ 

12.4 

—0.7 

_ 

25,  .        .         . 

0.5 

- 

11.0 

—1.0 

- 

26,  . 

0.7 

_ 

11.6 

—0.6 

_ 

27,  .        .         . 

1.5 

- 

11.6 

—1.0 

- 

28,  . 

1.3 

_ 

11.4 

—1.4 

_ 

29,  .        .        . 

1.7 

- 

11.0 

—1.0 

- 

30,  . 

1.7 

— 

10.7 

—2.0 

— 

80 


PHENOMENA  OF  PLANT-LIFE. 


Fluctuations  in  Mercurial  Gauge. 


DATE. 

Betula 
papyracea. 

DATB. 

Betula 
papyracea. 

DATE. 

Betula 
papyracea. 

1874. 

1874. 

1874. 

May    3, 

38.0 

May  16, 

—1.6 

May  29, 

—1.6 

4,        . 

36.0 

—5.6 

—2.8 

32.0 

17,        . 

—3.4 

30,        . 

—0.5 

39.0 

—2.0 

—1.8 

5,        . 

51.4 

1.3 

—2.8 

49.7 

18,        . 

—3.3 

31,       :. 

4.5 

46.0 

4.2 

—3.6 

6,        . 

49.0 

19,        . 

—3.4 

June  1, 

4.6 

54.0 

—2.4 

—3.7 

48.0 

—3.0 

—2.8 

7,        . 

48.5 

20, 

—4.3 

2,        . 

—4.7 

51.2 

—2.3 

3,        . 

—4.8 

45.8 

—3.0 

4, 

—4.6 

8,        . 

32.4 

21, 

—3.3 

i     5,     . 

—4.4 

48.8 

—2.4 

6,        . 

—4.4 

44.7 

—1.3 

7,        . 

—4.5 

9,        . 

28.1 

22,        . 

—2.4 

8,        . 

—5.0 

51.5 

—2.0 

9,        . 

—6.0 

47.0 

—2.7 

10,        . 

—5.4 

10,        . 

39.0 

23,        . 

—3.0 

11,        • 

—6.5 

48.0 

—1.1 

12,        . 

—6.0 

26.7 

—1.0 

13,        . 

—6.5 

11,        * 

7.0 

24,        . 

—2.0 

14,        . 

—7.0 

33.3 

0.6 

15,        . 

—5.4 

13.0 

—1.8 

16,        . 

—5.0 

12,      .., 

—2.7 

25,      i  <  ; 

—2.4 

17,        . 

4.7 

35.9 

—2.2 

18, 

—5.5 

20.0 

—2.0 

19,        . 

—5.2 

13,       £3 

—2.3 

26,       '. 

—2.3 

20, 

—5.6 

17.5 

—2.0 

22,        . 

—4.4 

—6.2 

—2.6 

23, 

—4.4 

14,  t     .. 

—2.5 

27,      ;  ,  i 

—4.0 

24,        . 

—5.0 

11.5 

—0.6 

25,        . 

—6.0 

—2.8 

—1.0 

26,        . 

—5.4 

15,        . 

—1.8 

28,     '.:; 

—3.8 

27,        . 

—6.0 

7.1 

—2.2 

28,        . 

—6.0 

11.6 

—2.4 

29,        ., 

—5.6 

16,        frj 

5.4 

29,        . 

—3.8 

30,        . 

—6.0 

PHENOMENA  OF  PLANT-LIFE. 


81 


Fluctuations  in  Mercurial  Gauges. 
ACER  SACCHARINUM. 


DATE. 

Gauge  1. 

Gauge  2. 

Gauge  3. 

Gauge  4. 

Gauge  5. 

1874—  Mar.  21,  . 

18.0 

18.0 

—6.8 

4.3 

6.0 

19.0 

19.3 

—3.3 

18.5 

3.5 

—1.2 

1.3 

—3.5 

5.0 

—1.5 

22,  . 

—4.0 

—2.0 

—3.5 

3.0 

—0.5 

—2.3 

0.5 

_ 

2.6 

- 

—5.5 

—6.0 

—2.5 

0.2 

_ 

23,  . 

_ 

—5.3 

—3.0 

7.7 

- 

27,  . 

4.3 

2.0 

—4.0 

—4.0 

- 

22.0 

24.0 

2.0 

15.2 

8.2 

25.5 

9.5 

—2.0 

6.4 

—0.3 

28,  . 

26.3 

10.0 

—3.0 

6.7 

- 

35.0 

32.0 

0.5 

19.7 

14.3 

16.0 

17.0 

1.0 

15.0 

—4.0 

29,  .        .        . 

25.0 

15.5 

0.6 

12.3 

—4.0 

12.6 

17.0 

1.0 

10.0 

2.3 

30,  . 

16.5 

,17.2 

1.1 

11.0 

0.3 

26.4 

24.0 

1.0 

14.0 

24.0 

22.8 

24.7 

0.2 

16.6 

6.0 

31,  . 

25.5 

12.2 

- 

9.0 

—23.0 

1.2 

15.0 

_ 

6.4 

8.2 

Apr.    1,  . 

3.3 

10.2 

1.0 

2.7 

9.0 

3.1 

10.0 

1.0 

3.0 

8.5 

18.0 

16.3 

3.0 

11.8 

16.9 

2 

19.0 

16.0 

1.5 

13.2 

12.5 

_ 

_ 

1.2 

8.0 

46.0 

_ 

_ 

0.6 

14.6 

8.0 

3,  . 

_ 

_ 

3.0 

5.0 

0.2 

17.5 

13.0 

_ 

13.9 

0.2 

4,  . 

2.2 

—6.8 

2.7 

4.0 

—2.0 

—1.7 

—4.0 

24 

4.0 

—1.4 

—1.0 

_ 

2.2 

3.6 

—1.6 

5,  .         .        . 

—1.6 

- 

1.0 

3.8 

—2.0 

—0.3 

—2.2 

1.0 

1.4 

_ 

15.5 

- 

1.4 

5.4 

1.2 

6,  .         .        . 

7.3 

11.1 

4.0 

4.0 

18 

25.1 

6.0 

1.4 

0.5 

1.2 

16.2 

14.0 

1.1 

10.9 

0.8 

7,  .        .        . 

—11.7 

3.0 

1.1 

1.0 

- 

250 

5.1 

1.4 

0.9 

23.0 

21.0 

12.3 

1.0 

11.1 

4.1 

8,  . 

—7.8 

—1.5 

1.1 

1.8 

—0.1 

26.1. 

6.1 

1.1 

11.3 

13.1 

12.1 

11.1 

1.1 

9.6 

—0.2 

9,  .        .        . 

—2.8 

6.1 

1.0 

3.4 

—1.7 

—1.0 

5.2 

1.0 

2.9 

1.1 

—4.0 

4.0 

1.0 

2.3 

1.4 

10,  .        .        . 

—6.1 

1.6 

0.8 

1.8 

—1.2 

1.6 

2.4 

1.0 

2.0 

—1.1 

—4.7 

2.5 

1.0 

1.4 

—1.1 

82  PHENOMENA  OF  PLANT-LIFE. 

Fluctuations  in  Mercurial  Gauges — Continued. 


DATE. 

Gauge  1. 

Gauge  2. 

Gauge  3. 

Gauge  4. 

Gauge  5. 

1874—  Apr.  11,  . 

—16.0 

—2.7 

1.0 

—2.3 

3.1 

12.0 

1.8 

1.0 

8.7 

—2.8 

2.0 

3.3 

1.0 

6.2 

—1.1 

12,  .        .        .  ' 

—0.7 

—0.4 

2.0 

—03 

—1.1 

_ 

_ 

1.0 

_ 

_ 

—10.7 

—0.3 

2.0 

—0.9 

—0.9 

13,  ... 

—9.6 

—0.3 

2.2 

4.0 

3.0 

1.6 

—0.5 

1.0 

—1.2 

—3.0 

15.0 

1.2 

1.0 

9.0 

3.3 

14,  .        .        . 

—6.1 

—0.4 

1.0 

—0.7 

3.8 

26.2 

3.1 

1.0 

11.4 

13.6 

17.0 

5.3 

- 

10.7 

1.3 

15,  .        .        . 

5.9 

5.6 

1.0 

8.4 

—0.6 

7.9 

6.4 

0.9 

82 

—0.4 

0.5 

6.1 

1.0 

6.9 

—0.3 

16,  .        .        . 

—6.5 

2.8 

1.0 

0.7 

—0.3 

—0.5 

3.0 

0.9 

0.7 

—0.3 

—2.8 

1.7 

1.0 

_ 

—0.3 

17,  . 

—5.3 

1.3 

1.0 

—1.2 

—0.2 

—36 

1.1 

1.2 

—1.3 

—0.2 

—33 

1.0 

1.1 

—1.6 

—0.3 

18,  . 

3.3 

—2.4 

1.5 

3.4 

22 

14.1 

—0.7 

1.0 

11.0 

21.0 

19.0 

—1.0 

0.9 

12.0 

4.7 

19,  .        .        . 

13.0 

—1.4 

1.0 

8.4 

—0.4 

15.0 

—3.0 

1.0 

10.2 

_ 

14.4 

—3.6 

0.8 

9.7 

_ 

20,  . 

5.0 

2.0 

0.9 

2.0 

- 

2.6 

1.8 

1.0 

1.4 

_ 

2.3 

1.9 

1.0 

1.0 

_ 

21,  .        .        . 

1.8 

1.9 

0.5 

- 

- 

2.1 

2.0 

0.8 

2.2 

2.0 

2.6 

2.2 

0.7 

1.4 

0.2 

22,  .        .        . 

—0.4 

1.3 

0.6 

—4.5 

_ 

2.0 

2.1 

0.7 

—5.3 

0.3 

3.1 

2.4 

0.5 

7.5 

0.2 

38,  -        .        . 

1.1 

18 

0.5 

1.0 

0.1 

1.1 

1.8 

0.5 

1.3 

0.2 

1.0 

1.8 

0.4 

1.0 

0.2 

24,  .        .        . 

- 

1.2 

0.2 

0.3 

0.2 

1.2 

2.0 

—2.6 

4.2 

0.3 

1.0 

2.0 

—4.0 

4.0 

0.3 

25,  -        .        . 

—0.6 

1.3 

—5.3 

- 

0.2 

—0.6 

1.4 

—5.0 

- 

_ 

—0.6 

1.3 

—5.0 

—2.0 

—0.2 

36,  .        .         . 

—2.1 

1.0 

—0.8 

—3.5 

1.0 

—1.7 

1.2 

—4.3 

10.6 

2.0 

27,  ..        .        . 

—1.5 

1.0 

—4.5 

80 

—1.0 

—1.0 

1.6 

—4.2 

87 

0.4 

28,  .        ,        . 

—3.4 

0.6 

—0.4 

2.8 

0.2 

—2.5 

1.1 

—8.3 

8.8 

0.3 

—2.0 

1.3 

—7.0 

9.8 

0.3 

29,  .        -        . 

—1.5 

1.2 

—5.6 

5.5 

0.5 

PHENOMENA  OF  PLANT-LIFE. 

Fluctuations  in  Mercurial  Gauges — Concluded. 


83 


DATE. 

Gauge  1. 

Gauge  2. 

Gauge  3. 

Gauge  4. 

Gauge  5. 

1874—  Apr.  30,  . 

—2.5 

1.5 

—5.9 

1.8 

0.7 

--2.6 

1.5 

—6.0 

2.0 

0.5 

—2.0 

1.6 

—5.8 

2.5 

0.6 

May    1,  .        .        . 

—2.5 

1.5 

—5.6 

1.1 

0.4 

—2.6 

1.9 

—5.9 

2.3 

0.6 

—2.9 

—  • 

—5.9 

_ 

0.6 

2,  .        .        . 

—35 

- 

—5.8 

- 

0.5 

—3.7 

_ 

—6.2 

0.6 

0.5 

—3.6 

- 

—6.2 

0.2 

0.6 

3,  .        .        . 

—4.8 

- 

—7.0 

—1.2 

0.4 

—4.0 

- 

—6.6 

3.0 

0.7 

4,  .        .        . 

—4.3 

- 

—7.0 

—2.0 

0.5 

—3.5 

- 

—6.0 

2.1 

0.5 

5,  .        .        . 

—26 

- 

—3.3 

—0.3 

0.6 

6,  ... 

—2.5 

- 

—3.2 

—2.1 

0.5 

—1.0 

- 

—3.0 

—0.8 

0.8 

7,  . 

—1.5 

- 

—3.0 

—2.1 

0.6 

—1.2 

- 

—27 

—2.0 

0.6 

8,  .        .        . 

—1.1 

- 

—3.1 

—2.1 

0.5 

—0.6 

_ 

—2.5 

—1.2 

0.9 

9,  .        .        . 

—0.6 

- 

—2.8 

—2.3 

0.6 

—0.1 

- 

—2.1 

—0.6 

0.8 

10,  .        .        . 

1.0 

- 

—2.8 

—1.3 

1.0 

1.3 

- 

—3.2 

—13 

0.9 

11,  . 

0.3 

- 

—3.0 

—1.3 

0.8 

12,  .        .        . 

1.2 

- 

—1.8 

—2.6 

0.1 

1.6 

— 

—0.5 

—2.1 

1.1 

13,  .        .        . 

0.9 

- 

—1.2 

—1.8 

1.0 

2.0 

- 

—0.3 

—2.0 

1.3 

14,  . 

0.1 

- 

—2.0 

—2.0 

1.0 

1.2 

- 

—2.4 

—1.7 

1.2 

15,  . 

- 

- 

—  4.2 

—2.1 

1.0 

1.4 

— 

— 

—3.0 

1.3 

16,  . 

0.4 

- 

- 

—2.0 

1.1 

0.4 

_ 

— 

—1.5 

1.1 

17,  . 

0.3 

- 

- 

—2.0 

1.0 

20,  . 

0.1 

_ 

_ 

—2.1 

1.0 

21,  .         .         . 

0.6 

— 

- 

—2.0 

1.0 

22,  .         .         . 

0.5 

- 

- 

—1.8 

0.8 

23,  .         .         . 

0.5 

- 

- 

—2.0 

0.6 

24,  . 

0.6 

- 

- 

—2.0 

1.2 

25,  .         .         . 

1.0 

- 

- 

—1.8 

1.0 

26,  . 

1.0 

— 

— 

—1.3 

1.4 

27,  .         .         . 

0.4 

_ 

_ 

—2.0 

1.3 

28,  . 

0.2 

- 

- 

—2.0 

1.4 

29,  .        .        . 

0.2 

— 

_ 

—2.0 

1.0 

30,  . 

0.2 

- 

-. 

—2.0 

1.0 

31,  .        .        . 

0.9 

_ 

_ 

—1.8 

1.5 

June  1,  . 

1.2 

- 

- 

—1.9 

1.4 

2,  .        .        . 

0.5 

- 

- 

--21 

0.8 

PHENOMENA  OF  PLANT-LIFE. 


Fluctuations  in  Mercurial  Gauges. 


DATE. 

Acer 
rubrum. 

Juglans 
cinerea. 

DATE. 

Acer 
rubrum. 

Juglans 
cinerea. 

1874. 

, 

1874. 

Mar.  28,     .        . 

2.1 

_ 

Apr,  11,     .        . 

3.9 

1.8 

9.2 

1.0 

1.4 

5.3 

2.5 

1.5 

12,     .        . 

9.0 

5.8 

29,     .        . 

3.2 

1.5 

6.6 

2.5 

2.3 

30 

13,     .        . 

7.8 

7.2 

30,     .        . 

5.2 

5.2 

5.0 

1.0 

3.2 

6.2 

10.0 

6.2 

2.2 

9.0 

14,     .        . 

11.4 

10.8 

31,     .        . 

2.5 

10.5 

_ 

10.4 

2.4 

2.8 

13.1 

7.3 

Apr.     1,     .        . 

2.0 

5.0 

15,     .        . 

2.1 

3.7 

2.0 

4.0 

4.2 

4.6 

2.3 

6.3 

—1.0 

2.4 

2,     .        . 

2.2 

4.6 

16,     . 

—1.9 

0.5 

2.1 

2.6 

—2.5 

2.8 

2.0 

6.8 

—1.8 

—0.4 

3,     .        . 

2.2 

5.0 

17,     .        . 

—0.6 

0.8 

2.4 

4.0 

—0.4 

1.2 

4,      .      -. 

2.2 

1.8 

0.3 

1.1 

2.2 

1.0 

18,     .        . 

1.7 

1.1 

2.2 

1.6 

8.4 

7.0 

5,     .        . 

2.2 

1.0 

2.6 

6.6 

~ 

1.5 

19,     .        . 

—1.1 

4.0 

_ 

0.9 

3.4 

5.8 

6,     .        .' 

_ 

1.0 

0.5 

1.3 

- 

1.5 

20,     .        . 

1.9 

1.0 

_ 

2.7 

2.0 

1.0 

7,     .       .. 

14.0 

4.7 

2.0 

0.8 

9.8 

3.7 

21,     .        . 

1.9 

1.2 

11.1 

5.0 

2.0 

1.0 

8,     . 

16.1 

4.4 

1.7 

1.0 

16.4 

4.0 

22,     .   *    . 

7.5 

0.9 

9.3 

5.1 

3.0 

— 

9,     . 

3.0 

1.3 

3.0 

- 

3.9 

2.0 

23,     .        . 

0.9 

- 

1.8 

0.9 

1.2 

_ 

10,     .        . 

1.0 

0.3 

1.2 

- 

4.1 

2.0 

24,     .         . 

8.0 

- 

—1.4 

—0.7 

6.0 

- 

11,     . 

2.1 

—0.5 

2.0 

PHENOMENA  OF  PLANT-LIFE. 


85 


TABLE — Showing  the  Temperature  and  amount  of  Cloudiness  in  Amherst 
during  the  months  of  March,  April,  May  and  June,  1874.  By  Prof.  E.  S. 
SNELL,  LL.D.,  of  Amherst  College. 


MARCH,    1874. 


DAT  OF  MONTH. 

TEMPERATURE. 

CLOUDINESS. 

7A.M. 

2  P.M. 

9  P.M. 

Mean. 

7A.M. 

2P.M. 

9P.M. 

1                               ... 

20.4 
28.0 
33.3 
52.7 
26.9 
20.0 
29.0 
30.5 
29.2 
17.2 
20.3 
12.0 
13.0 
19.0 
21.3 
25.0 
34.7 
39.9 
45.9 
38.3 
28.0 
37.0 
26.0 
9.7 
22.0 
40.3 
281 
30.0 
26.0 
30.1 
30.0 

40.6 
50.3 
54.0 
56.0 
40.4 
34.9 
33.9 
35.8 
29.5 
23.1 
19.1 
22.7 
20.0 
32,0 
40.1 
44.0 
40.5 
55.7 
54.0 
42.2 
50.0 
41.3 
29.7 
23.5 
46.7 
57.2 
39.0 
41.0 
33.3 
48.7 
32.2 

35.0 
42.0 
49.5 
36.2 
30.0 
32.7 
33.7 
31.8 
23.0 
21.0 
17.0 
16.0 
17.5 
26.0 
33.5 
37.0 
39.9 
52.7 
51.8 
33.3 
39.0 
30.7 
19.5 
22.5 
37.7 
45.0 
29.2 
34.2 
25.5 
34.8 
27.2 

32.0 
40.1 
45.6 
48.3 
32.4 
29.2 
32.2 
32.7 
27.2 
20.4 
18.8 
16.9 
16.8 
25.7 
31.6 
35.3 
33.4 
49.4 
50.6 
37.9 
39.0 
36.3 
25.1 
18.6 
35.5 
47.5 
32.1 
35.1 
28.3 
37.9 
29.8 

>          8 

1 
10 

2 
10 
8 
8 
7 
10 
3 
6 
1 

7 
10 
10 
10 
5 

8 
1 

8 
1 
10 
9 

-L 

\      48  pe 

4 
5 

8 
10 
7 
7 
9 
10 
3 
4 

7 
10 
10 
10 
3 
7 
2 
8 
7 
2 
9 
1 
4 

5 
10 

1 

8 
3 

10 
10 
2 
5 
10 
10 

8 
10 
10 
10 

5 
1 
3 
5 

7 

2   

3 

4,.    ...... 

?•::::::: 

I::   :::::: 

10  

11  

12,  
13,  
14  

15  

16 

17   

18 

19  

20,  . 
21,  . 
22,. 
23,. 
24,. 
25,  . 
26,. 
27,. 
28,. 
29,  . 
30  

31  
Mean,     ..... 

- 

- 

- 

32.96 

r  cent,  o 

f  sky. 

APRIL,    1874 


1,  

1:  :  :  :  :  :  : 

5!  ! 

18.7 

28.0 
33.7 
28.3 
21.5 
31.5 
32.4 
29.9 
37.0 
35.0 
34.0 
21.0 
23.3 
35.0 
51.2 
38.C 
37.0 
31.0 
35.3 
40.0 
38.0 
37.5 
37.6 
35.0 
37.2 
32.8 
39.0 
36.0 
33.9 
33.0 

34.0 
44.8 
42.0 
31.0 
41.0 
41.5 
42.3 
57.0 
44.0 
41.7 
45.2 
30.0 
42.3 
63.0 
61.0 
49.8 
33.7 
48.3 
61.0 
38.7 
49.0 
51.0 
39.0 
51.2 
34.7 
43.2 
48.0 
45.5 
36-3 
41.0 

31.3 
33.7 
35.0 
18.5 
28.2 
33.3 
36.3 
46.8 
40.0 
37.5 
31.0 
24.7 
33.5 
53.0 
54.0 
420 
31.5 
36.5 
48.0 
36.5 
38.0 
39.0 
34.0 
41.3 
32.0 
36.5 
35.0 
35.0 
34.3 
39.8 

28.0 
38.8 
36.9 
25.9 
30.2 
35.4 
37.0 
44.6 
40.3 
38.1 
36.7 
25.2 
36.4 
50.3 
55.4 
43.3 
34.1 
38.6 
48.1 
38.4 
41.7 
42.5 
36.9 
42.5 
34.6 
37.5 
40.7 
38.8 
34.8 
37.9 

10 
9 
10 

10 
10 
1 
10 
10 

9 
8 
10 

10 
10 
10 
5 
10 
1 
10 
10 
5 
1 
10 
9 

1 
3 

8 
2 
5 
10 
8 
10 
7 
9 

5 

9 
2 
10 
5 

10 
5 
2 

10 
7 
10 
8 
1 
10 
10 
8 

10 
4 
10 

10 
10 
10 

3 
10 

2 
10 
9 
5 
10 
5 
10 
5 

10 
9 

2 

e,.  .  .  : 

7 

8  

9,  
10  

11,  
12,  
13  

14,  

15  

16,  . 

17, 

18,  . 

19,  . 

20,  . 

21,  . 

22,  . 

23;  : 

24  

25,  .. 

26,  

27  

28,  

29  

30,  .    .    .   ,  . 
Mean,  

- 

- 

- 

.  38.32 

56  per  cent,  of  sky. 

12 


86 


PHENOMENA  OF  PLANT-LIFE. 


TABLE — Showing  Temperature,  etc. — Con. 
MAY,   1874. 


DAY  OF  MONTH. 

TEMPERATURE. 

CLOUDINESS. 

A.M. 

2P.M. 

9  P.M. 

Mean. 

7  A.M. 

2  P.M. 

9  P.M. 

1,.       

39.5 

44.0 
43.8 
40.9 
46.0 
43.0 
39.0 
41.0 
44.5 
71.0 
49.8 
44.0 
50.2 
62.0 
54.0 
50.2 
52.8 
52.4 
51.5 
48.3 
51.5 
48.0 
50.0 
57.2 
57.3 
62.0 
53.8 
58.2 
62.0 
62.2 
63.0 

46.0 
43.0 
57.0 
63.5 
58.9 
59.0 
49.3 
58.0 
68.6 
85.0 
60.8 
66.0 
80.5 
78.5 
74.0 
53.0 
68.0 
58.0 
61.1 
64.0 
57.1 
57.0 
66.8 
71.7 
59.8 
61.0 
72.0 
80.0 
86.0 
82.6 
82.8 

43.0 
36.5 
46.5 
51.0 
48.3 
47.0 
37.0 
45.0 
62.5 
54.8 
44.2 
50.0 
63.0 
60.0 
56.0 
51.5 
55.0 
54.0 
49.0 
56.5 
49.5 
49.0 
56.0 
59.5 
60.3 
50.2 
60.5 
640 
67.0 
69.0 
68.3 

42.8 
41.2 
49.1 
51.8 
51.1 
49.7 
41.8 
48.0 
58.5 
70.3 
51.6 
53.3 
64.6 
66.8 
61.3 
51.6 
58.6 
54.8 
53.9 
56.3 
52.7 
51.3 
57.6 
62.8 
59.1 
57.7 
62.1 
67.4 
71.7 
71.3 
71.4 

1 

8 

3 

7 

7 
8 
5 
9 

2 
1 

10 
7 
8 
5 
3 
10 
8 

7 
10 
2 
1 

2 
10 

8 
9 

9 
8 
8 
8 
7 
5 

2 

2 
1 
1 

10 

10 
3 
9 
10 
8 
8 
8 
10 
9 
3 

1 
1 

7 

9 

5 

2 
10 

2 

3 
10 
1 
10 

10 
10 
6 
1 
9 
9 

1 

6 

7 
10 

t   :::::: 

4 

!     ;                 ; 

?;:   :::::: 

ft:    :::::: 

10  

11  .    •  

12  

13,  

15  
16  

17,  
18  
19  
20,  

22,  . 

23  .                         .... 

24  
25t  
26,  
27,  .                 

28,  
29  

30  
31  

Mean              .... 

- 

- 

- 

56.52 

45  per  cent,  of  sky. 

JUNE,    1874 


1  . 

62.5 
51.3 
54.5 
57.3 
62.2 
67.0 
67.0 
71.0 
63.8 
69.0 
57.0 
56.5 
56.0 
55.5 
59.0 
65.0 
64.5 
64.7 
62.9 
54.2 
58.5 
60.0 
70.0 
66.4 
61.0 
64.0 
63.0 
64.5 
73.3 
68.2 

66.8 
65.0 
68.3 
66.7 
71.0 
75.5 
77.5 
78.0 
81.0 
77.0 
62.0 
68.0 
61.0 
72.9 
77.5 
74.0 
71.7 
71.8 
69.0 
65.2 
75.0 
82.3 
85.0 
72.1 
75.5 
70.0 
77.2 
87.0 
93.0 
76.5 

55.0 
55.5 
55.0 
64.5 
60.8 
68.0 
71.8 
66.2 
66.5 
62.0 
56.0 
64.0 
53.5 
61.0 
64.5 
65.0 
63.2 
63.7 
54.0 
59.5 
66.8 
71.5 
71.0 
62.0 
67.0 
60.1 
68.7 
76.0 
71.0 
60.0 

61.4 
57.3 
59.3 
62.8 
64.7 
70.2 
72.1 
71.7 
70.4 
69.4 
58.3 
62.8 
56.8 
63.1 
67.0 
68.0 
66.5 
66.7 
62.0 
59.6 
66.8 
71.3 
75.3 
66.8 
67.8 
64.7 
69.6 
75.8 
79.1 
68.2 

6 

8 
10 
10 
10 
10 

7 
7 
8 
10 
5 

1 
6 
10 
10 
2 
8 
10 
5 
4 
1 
5 
10 
10 

7 
2 

8 
1 
5 
10 
10 
10 
9 
3 
3 
1 
10 
9 
7 
7 
5 
7 
10 
8 
8 
9 
6 
3 
8 

4 
9 
1 
1 
2 

5 

9 

10 
9 
10 
1 
10 
3 

10 
8 

1 
10 
8 
7 
10 
9 
8 
5 
5 
5 
8 
10 

9 

£:::::: 

1 

e.  :::::; 

7,  .    .   .   .    . 

8  
9,  

£:  :::::: 

12  ....... 

It  :::::: 

$:  :::::: 

17  
18  
19  

20  

21,  

22  
23  

24  
25  
26     

27  

28,  .    .   .   .  '  "  . 

St:  :::::: 

Mean      .... 

•  ''.  -i 

- 

66.18 

58  per  cent,  of  sky. 

PHENOMENA  OF  PLANT-LIFE. 


87 


TABLE 

Showing  the  Percentage  of  Water  in  the  wood  and  bark  of  the 
branches  and  roots  of  certain  species  of  trees  at  different  seasons  of 
the  year. 


GENUS. 

Species. 

Description. 

PERCENTAGE  OF  WATER. 

Feb. 

April. 

Sept. 

Dec, 

Abies 

Canadensis.   . 

One  year, 

48.66 

Two  year, 

49.62 

- 

- 

- 

Root,   . 

_ 

55.96 

_ 

- 

Dead  twig,* 

18.76 

_ 

_ 

- 

Abies 

excelsa.  . 

One  year, 

45.50 

_ 

- 

_ 

Two  year, 

44.28 

- 

- 

- 

Dead,2  . 

17.03 

_ 

— 

— 

Acer 

rubrum.         .        . 

One  year, 

44.88 

_ 

- 

- 

Two  year, 

44.71 

_ 

- 

_ 

Acer 

saccharinum. 

One  year, 

46.50 

_ 

48.10 

47.36 

Two  year, 

47.13 

_ 

44.05 

47.00 

Sap-wood, 

_ 

_ 

_ 

41.23 

Heart-wood 

_ 

_ 

- 

40.12 

Dead,  . 

18.85 

- 

_ 

_ 

Root,   . 

- 

41.44 

44.05 

- 

JEsculus  . 

Hippocastanura.    . 

One  year, 
Two  year, 

49.14 
46.08 

: 

59.68 
59.05 

: 

Ailantus  . 

glandulosa.    . 

One  year, 

48.56 

_ 

- 

_ 

Two  year, 

46.00 

- 

_ 

- 

Alnus 

incana.   . 

One  year, 

50.47 

_ 

- 

- 

Two  year, 

51.45 

_ 

- 

- 

Betula      . 

alba  v.  populifolia. 

One  year, 
Two  year, 

46.24 
42.00 

54.97 
55.64 

53.90 
48.52 

: 

Root,   . 

- 

--•^ 

42.63 

- 

Dead,  . 

15.13 

_ 

_ 

_ 

Betula 

lenta.     . 

One  year, 

38.25 

_ 

_ 

41.80 

Two  year, 

40.54 

- 

- 

40.73 

Root,   . 

_ 

_ 

49.61 

_ 

Dead,  . 

13.65 

_ 

_ 

Carpinus  . 

Americana.    . 

One  year, 

38.70 

_ 

57.68 

_ 

Two  year, 

39.41 

- 

48.69 

- 

Dead,  . 

13.84 

_ 

_ 

_ 

Carya 

amara.   . 

One  year, 

_ 

_ 

_ 

33.26 

Two  year, 

- 

- 

- 

31.23 

Root,   . 

_ 

54.32 

_ 

_ 

Fagus 

ferruginea.     . 

One  year, 

44.42 

- 

- 

Two  year, 

44.69 

_ 

_ 

_ 

Juglans    . 

cinerea.  . 

One  year, 

45.51 

_ 

54.22 

_ 

Two  year, 

46.73 

_ 

51.41 

_ 

Nyssa 

multiflora. 

One  year, 

50.95 

_ 

51.14 

_ 

Two  year, 

48.93 

_ 

50.93 

_ 

Pinus 

Strobus. 

One  year, 

- 

56.31 

62.90 

_ 

Two  year, 

- 

55.52 

58.34 

_ 

Dead,2  . 

11.90 

_ 

_ 

- 

Root,   . 

_ 

_ 

67.65 

_ 

Platanus  . 

occidentalis.  . 

One  year, 

54.46 

52.55 

_ 

Two  year, 

51.44 

53".79 

_ 

_ 

Populus    . 

tremuloides.  . 

One  year, 

4977 

53.30 

_ 

Two  year, 

50.86 

_ 

51.00 

_ 

Primus     . 

Persica.  . 

One  year, 

46.13 

_ 

_ 

_ 

Two  year, 

40.39 

•" 

™* 

"™ 

PHENOMENA   OF  PLANT-LIFE. 


Percentage  of  Water  in  Trees — Continued. 


GENUS. 

Species. 

Description. 

PERCENTAGE  OF  WATER. 

Feb. 

April. 

Sept. 

Dec. 

Prunus     . 

serotina. 

One  year, 

_ 

_ 

50.00 

_ 

Two  year, 

_ 

_ 

50.34 

-  _ 

Dead,  . 

17.37 

— 

- 

- 

Pyrus 

communis.     . 

One  year, 

49.85 

55.39 

54.05 

_ 

Two  year, 

47.70 

54.03 

51.48 

- 

Root,   . 

_ 

_ 

60.39 

- 

Pyrus 

Malus.    . 

One  year, 

49.49 

48.98 

56.18 

— 

Two  year, 

44.75 

46.76 

54.49 

— 

Root,   . 

_ 

64.82 

54.78 

— 

Dead,  . 

12.88 

_ 

_ 

- 

Quercus    . 

alba.       . 

One  year, 

38.01 

41.24 

43.06 

- 

Two  year, 

35.23 

36.74 

39.51 

— 

Root,   . 

_ 

53.07 

51.28 

- 

Dead,  . 

15.47 

_ 

- 

- 

Salix 

alba.      . 

One  year, 

49.88 

_ 

53.07 

— 

Two  year, 

51.65 

_ 

49.73 

— 

Root,   . 

_ 

_ 

68.38 

- 

Tilia 

Americana.    . 

One  year, 

55.10 

_ 

48.62 

— 

Two  year, 

53.93 

— 

55.97 

- 

Ulmus 

Americana.    . 

One  year, 

41.37 

— 

57.14 

- 

Two  year, 

39.77 

- 

52.31 

— 

Root,   . 

- 

45.26 

43.19 

— 

Dead,  . 

13.46 

_ 

_ 

— 

Vitis 

sestivalis. 

One  year, 

41.86 

43.77 

_ 

- 

Two  year, 

41.08 

43.66 

_ 

- 

Root,   . 

" 

55.11 

PHENOMENA  OF  PLANT-LIFE. 


89 


TABLE 

Showing  the  specific  gravity  of  the  Sap  collected  from  various  trees  in  Spring,  with  observations  concerning  the  cane  sugar,  glucose 
and  starch  contained  in  them.  By  CHARLES  WELLINGTON,  B.  S. 

TROMMER'S  COPPER  REDUCTION  TEST. 

reduce  ten  cubic  centimeters 
's  solution. 

Sap  after  being  treated  with 
hydrochloric  acid. 

1     1  "S  -               ,     1     1  -----     1 

rely  to  the  presence  of  glucose,  the  several'  percentages  of  sugar, 

X?v^^\ 
/vs?  *  '  i  •  I 

^^MJ'/ 

0 

o 

rg^^^S                        S      S       -       3       S 

CO  -rH  O  iO  >O              p  CO  CO  p  O 
1       I    rH  CO  CO  CO  CO     1       |    CO  CO  CO  CO  GO     1 

Quantity  of  sap  required  to 
of  Fehling 

Fresh  Sap. 

1      1     0  "                          1      1    "                                1 

o 

|3    3    3    3               333S    , 

O 

P  P  H  —  r~r"         co  p  p  »q  o 

PERCENTAGE  COMPOSITION. 

•UOJBJS 

•auipoj  qjjAV  UOH3B3J  B 
£niuiB)qo  ut  aouB;su{  ^UB  u\  POODDHS  ?ou  pja 

%       ^ 

OOt^iOCOO''MOOOGO^OOO 

*  Taking  it  for  granted  that  the  reduction  of  the  copper  solution  in  the  several  instances,  was  due  enti 
as  given  above,  are  correct.  This,  however,  for  obvious  reasons,  remains  an  assumption,  to  some  extent, 
t  The  quantity  of  sap  was  insufficient  to  allow  of  taking  the  specific  gravity. 

OOGNi-'OO'-HOOO^HrHOOO 

•adBJQ 

-puao  soaoSap   uaaj 
-ju  JB  A"jiABJ3  onpads 

<N   g  .0  0  0  r-  0              ^  10  0  (M  0 

8^00080         88088 

•  S 

Q 

(M  CM 

GO  GO                 »-H                               t^I  J[J 

<M(M               CO                           GN^, 

S'°S^GOG0^^^C0^^^^^ 

^       fe        ^        *2  b       ^  '2        *-'        b 

«                                           ^H                ^      ®5                   —    ^                  p)^ 

OJ 

M 

a 
-  .     .§  . 

•  a        .-a    j.s  ' 

.S.2.S       •  ^  j?    .?3   .    .  § 

lllllllllllilll  . 

OQ 
W 

O 

tn  p  C  ^        ^^ 

uaqranjj; 

^CNCO^^COt-OOOiO^<MCO^O 

90  PHENOMENA   OF  PLANT-LIFE. 


REMARKS. 

Specimen  No.  2  was  the  colorless,  translucent  gum  which  exudes 
freely  from  the  wood  of  the  root  and  stem  of  the  grape  vine,  at  any  time 
during  the  long  period  of  nearly  eight  months,  when  the  vital  force  is 
dormant.  It  was  entirely  free  from  grape  sugar,  cane  sugar,  or  starch. 
When  treated  with  water,  it  swelled  up  and  appeared  to  be  partly  solu- 
ble and  partly  not.  The  large  amount  of  ash  contained  an  abundance  of 
lime. 

Specimen  No.  5  was  sap  from  a  red  maple  which  had  been  girdled 
about  two  years  previous.  No.  6  was  sap  from  a  red  maple,  in  a  nor- 
mal condition,  which  stood  not  far  from  No.  5.  It  was  placed  in  the 
list  in  order  that  it  might  be  compared  with  No.  5. 

Specimen  No.  8  was  a  very  small  quantity  of  sap  from  an  apple  tree. 
When  brought  in,  it  very  much  resembled  cider  in  color.  It  had  an  un- 
pleasant, sour  taste. 

Specimen  No.  13  was  sap  from  an  ironwood.  Though  somewhat  tur- 
bid, this  sap  contained  no  solid  particles  which  could  be  separated  by 
filtration.  About  two  quarts  of  the  sap  which  flowed  on  the  day  of  May 
7th,  and  the  same  amount  which  flowed  during  the  following  night, 
were  collected  and  allowed  to  stand  in  the  laboratory  for  some  months. 
They  became  milky  in  a  very  short  time,  and  fermented  quite  rapidly, 
emitting  a  very  offensive  odor.  There  was  no  difference  between  the 
two  in  this  respect,  so  far  as  could  be  determined  by  their  external 
appearance. 

On  the  seventh  of  May,  the  sweet  exudation  from  the  hickory  was 
tested  for  cane  sugar.  By  means  of  alcohol  it  was  removed  to  a  glass 
plate,  and  when  dry  was  examined  under  the  microscope ;  it  was  also 
treated  with  Fehling's  copper  solution ;  but  neither  test  showed  a  trace 
of  cane  sugar.  Grape  sugar  was  indicated  to  be  present  in  abundance. 

Gas  from  Sap  of  Acer  saccharinum. 

On  the  twenty-seventh  of  April,  two  and  a  half  quarts  of  the  first  run  of 
sap  from  a  sugar  maple  was  collected  for  examination  in  regard  to  the 
composition  of  the  gas  contained  in  it.  By  boiling,  gas  was  obtained 
from  this  sap  which  measured  31.2  cubic  centimetres  at  18°  C.  By  intro- 
ducing a  certain  amount  of  potassium  hydrate,  the  volume  was  reduced 
to  29.5  cubic  centimetres  at  18°  C.,  owing  to  the  absorption  of  carbonic 
acid  by  the  potassium  hydrate.  By  inserting  a  certain  amount  of  gallic 
acid,  the  volume  was  again  reduced  to  22.5  cubic  centimetres  at  18°  C., 
due  to  the  absorption  of  oxygen,  thus  leaving  22.5  cubic  centimetres  of 
nitrogen. 

Composition  by  Volume. 

Gas  from  Sugar  Maple.        Atmospheric  Air. 

Nitrogen,     .        .       ,..;     .        .        .    72.213  79.02 

Oxygen,      .        ....        .        .    22.435  20.94 

Carbonic  acid, 5.352  0.04 

100.000  100.00 


PHENOMENA  OF  PLANT-LIFE.  91 

Large  quantities  of  sap  from  specimens  of  Vitis  aestivalis,  Acer  sacchar- 
inum,  Acer  rubrum,  Juglans  nigra,  Ostrya  Virginica,  and  Betula 
lutea,  have  been  evaporated  preparatory  to  making  analyses  of  their  min- 
eral constituents.  This  work  has  not  yet  been  accomplished,  for  lack  of 
time. 


EXPLANATION  OP  FIGURES. 

FIG.    1  represents  two  nodes  of  the  squash  vine. 

A  is  the  petiole  of  a  leaf  showing  vertical  strise. 

B,  a  staminate  flower  on  a  long  peduncle. 

C,  a  branching  tendril  exhibiting  the  mode  of  attachment  to 

a  support,  and  the  double  reversed  spiral  of  the  portion 
between  the  support  and  the  base  of  the  tendril,  by  which 
all  the  branches  of  a  tendril  are  made  to  bear  their  share 
of  the  strain,  if  they  secure  an  attachment ;  and  by  which 
also  great  elasticity  is  given  to  the  tendril,  and  the  liabil- 
ity of  rupture  largely  diminished. 

D,  nodal  roots. 

E,  a  pistillate  flower  with  a  short  peduncle. 

F,  a  lateral  branch  of  the  vine. 

G,  a  tendril  Which,  having  failed  in  finding  a  support,  has 

coiled  upon  itself  and  turned  back  towards  the  older  por- 
tion of  the  vine. 

FIG.    2  illustrates  the  structure  of  the  tip  of  a  squash  rootlet,  the  cells  of 
the  epidermis  being  often  produced  into  root-hairs  consisting 
of  single  elongated  cells,  which  increase  immensely  the  absorb- 
ing surface. 
FIG.    3  shows  a  transverse  section  of  a  rootlet. 

A,  epidermis  with  root-hairs. 

B,  ordinary  cellular  tissue. 

C,  a  fibro-vascular  bundle. 

D,  loose  parenchyma  of  the  central  portion  of  the  rootlet. 
FIG.    4  is  a  longitudinal  section  of  rootlet. 

A,  epidermis  with  root-hairs. 

B,  cellular  tissue. 

C,  a  dotted  duct. 

FIG.  5  illustrates  the  structure  of  cork  or  periderm  from  a  squash.  The 
cells  are  large,  thin- walled,  dry  and  brown.  They  are 
developed  in  a  radial  manner  from  any  highly  vitalized  cel- 
lular tissue,  when  it  is  exposed  to  the  air.  Every  place  upon 
the  soft  parts  of  a  growing  plant  which  is  wounded  soon 
covers  itself  with  this  protecting  layer  of  cork. 

FIG.    6  is  a  transverse  section  of  a  squash  vine. 

A,  the  irregular  internal  cavity. 

B,  fibre-vascular  bundles. 

C,  the  outer  green  layer  of  the  bark. 


92  PHENOMENA   OF  PLANT-LIFE. 

FIG.    7  is  a  transverse  section  of  the  petiole  of  a  leaf. 

A,  internal  cavity. 

B,  fibro-vascular  bundles. 

C,  vertical  dark  green  striae  between  the  bundles,  consisting  of 

parenchyma  containing  chlorophyl. 
FiG.    8  exhibits  a  transverse  section  of  the  branch  of  a  tendril. 

A,  the  inner  sensitive  surface  of  loose  cellular  tissue,  which 

contracts  and  expands  as  the  branch  coils  and  uncoils. 

B,  bast  fibre  or  elongated  fusiform  cells. 

C,  fibro-vascular  bundles 

FIG.  9  represents  the  androaciuni  of  the  staminate  flower  with  connected 
sinuous  anther  cells,  which  are  open  and  discharging  pollen 
grains. 

FIG.  10  is  a  pollen  grain  oi  spherical  form  and  covered  with  projecting 
spines. 

A  is  the  opening  in  the  outer  membrane  through  which  the 
tube  develops  after  its  lodgment  on  the  stigmatic  surface 
of  the  pistil. 
FIG.  11  shows  the  gynsecium  of  the  pistillate  flower. 

A,  ovary. 

B,  style. 

C,  stigma. 

FIG.  12  is  a  vertical  section  of  the  pistil. 

A,  the  receptacle,  or  stem. 

B,  the  wall  of  the  ovary,  the  fibres  of  which  are  arranged  in 

three  distinct  layers.  The  outer  and  inner  ones  have  the 
fibres  extending  from  the  base  to  the  apex  of  the  ovary, 
or  young  squash,  while  the  central  one  consists  of  fibres 
running  around  the  ovary  at  right  angles  to  the  other 
two. 

C,  ovules  imbedded  in  loose  cellular  tissue. 

D,  canal  of  the  style  through  which  the  pollen  tubes  find  their 

way  to  the  ovules. 
FIG.  13  represents  a  transverse  section  of  the  ovary,  showing  the  three 

layers  of  the  tissues  of  the  wall  and  the  cells  of  the  ovaiy  with 

ovules  attached  to  the  inner  edges  of  the  carpellary  leaves. 
FIG  14  exhibits  the  propagating  pit  with  the  squash  in  harness,  and  the 

squash  root  of  a  second  vine  attached  to  a  mercurial  gauge  to 

show  the  pressure  of  the  sap. 

A,  the  box  in  which  the  squash  was  placed. 

B,  the  lever  to  support  the  weights. 

C,  the  root  from  which  the  principal  vine  grew. 

D,  the  root  of  the  vine  which  was  cut  off  when  eight  weeks 

old,  and  connected  with  a  gauge. 

E,  mercurial  gauge. 

F,  scale  to  indicate  the  variations  in  the  position  of  the  lever. 
FIG.  15  gives  a  view  of  the  apex  and  lower  side   of  the  squash,  after  it 

had  completed  its  growth,  and  been  taken  from  the  box  in 
which  it  had  been  confined. 


PHENOMENA  OF  PLANT-LIFE.  93 

FIG.  16  shows  the  top  of  the  squash,  with  the  marks  of  the  harness  irons 
upon  it. 

FIG.  17  represents  a  piece  of  the  root  of  an  apple  tree  which  penetrated 
a  bed  of  coarse,  dry  gravel,  to  the  depth  of  more  than  eight 
feet,  and  as  it  enlarged  adapted  itself  to  the  spaces  between 
the  pebbles,  and  in  some  cases  entirely  inclosed  them. 

FIG.  18  illustrates  the  manner  in  which  the  roots  of  a  black  spruce  grew 
on  Moose  Mountain,  in  New  Hampshire.  The  soil  was  only 
a  few  inches  deep,  and  below  was  solid  rock,  so  that  as  the 
horizontal  roots  increased  in  diameter,  they  lifted  themselves 
out  of  the  ground,  and  of  course  raised  the  entire  tree  every 
year. 

FIG.  19  shows  how  the  heart  of  a  yellow  birch,  growing  on  a  ledge  in 
Hanover,  N.  H  ,  has  been  carried  upward  and  outward  by  the 
annual  deposition  of  wood,  from  the  rock  on  which  it  must 
have  rested  when  the  seed  germinated  The  peculiar  thick- 
ening of  the  trunk  and  roots  near  the  base  is  often  seen  in 
trees  on  exposed  situations. 

FIG.  20  is  a  section  of  the  stem  of  a  tree  (Hibiscus  splendens)  about  four 
inches  in  circumference,  from  which  all  the  bark  and  most  of 
the  wood  was  removed.  A  portion  of  the  outer  layer  of  sap- 
wood,  one  inch  long  and  seven-sixteenths  of  an  inch  in  circum- 
ference, was  left  to  convey  the  sap  to  the  foliage,  which  had  a 
surface  of  twenty-five  hundred  square  inches.  Not  a  leaf 
wilted,  but  the  supply  of  water  was  abundant  for  the  growing 
tree 

FIG.  21  exhibits  a  section  of  a  similar  stem  from  a  portion  of  which 
the  wood  was  entirely  removed,  while  the  greater  part  of 
the  thick,  succulent  bark  remained.  The  foliage  had  a  surface 
of  five  hundred  square  inches,  while  the  amount  of  living  bark 
which  formed  the  connection  between  it  and  the  roots  was  at 
least  five  times  as  large  as  the  piece  of  sap-wood  in  the  pre- 
ceding figure.  The  leaves  wilted  as  quickly  and  completely 
as  if  the  stem  had  been  entirely  severed. 

FIG.  22  is  a  piece  of  wood  from  a  red  maple,  which  threw  out  a  callous 
from  its  ends  like  a  grape  cutting,  and  grew,  although  it  had 
neither  roots  nor  buds. 

FIG.  23  shows  a  section  of  an  elm  root  which  was  girdled,  inclosed  in  a 
glass  tube  so  as  to  exclude  the  air,  and  then  replanted  in  the 
earth,  its  connection  with  the  tree  remaining  intact  A  new 
bark  and  layer  of  wood  formed  from  the  cambium  which  had 
been  previously  deposited. 

FIG.  24  exhibits  a  section  of  the  trunk  of  a  small  elm,  upon  the  bark  of 
which  a  horizontal  incision  was  made,  and  above  this  four 
vertical  incisions  three  inches  long.  The  four  quarters  of  the 
bark  were  then  turned  up,  and  a  piece  of  tinned  copper,  one 
inch  wide,  was  wrapped  around  the  wood.  The  bark  was 
then  replaced,  covered  with  waxed  cloth,  and  securely  fas- 
tened down.  This  was  do-ne  on  the  thirtieth- of  May. 
13 


94  PHENOMENA  OF  PLANT-LIFE. 

FIG.  25  shows  the  section  as  arranged  for  the  experiment  of  determining 
whether  the  new  layer  of  wood  would  be  developed  from  the 
old  wood  or  from  the  bark. 

FIG.  26  represents  the  appearance  of  the  new  wood  (b)  which  was  deposited 
upon  the  metal,  (a)  after  the  removal  of  the  bark  in  September. 

FIG.  27  gives  the  microscopic  structure  of  a  horizontal  section  of  the 
elm  wood  and  bark  directly  over  the  metal.  Next  to  the  tin 
was  a  thin  layer  of  parenchyma,  (a)  connected  to  the  inner  layer 
of  bark  by  medullary  rays,  (c)  which  were  as  numerous  as  in 
the  other  parts  of  the  new  wood,  and  passed  directly  from  the 
bark  to  the  metal,  whether  examined  in  a  horizontal  or  verti- 
cal section.  The  cork  cells,  (f)  bast  (d)  and  parenchyma  (e) 
of  the  bark,  and  the  woody  fibre,  (b)  ducts  (g)  and  medullary 
rays  of  the  stem,  are  clearly  visible  in  this  section? 

FIG.  28  is  a  view  of  the  longitudinal  section  of  the  branch  of  an  apple 
tree  which  was  girdled  in  May,  1870.  After  growing  four 
years  and  bearing  fruit,  it  was  cut  in  1874.  There  were  then 
many  dead  twigs  upon  it,  and  it  was  evidently  in  declining 
health.  The  section  shows  how  the  sap-wood  was  becoming 
dry,  and  changing  into  heart  wood,  so  that  the  channel  for 
the  transmission  of  the  sap  from  the  roots  to  the  leaves  was 
almost  closed.  The  girdling  was  complete,  so  that  the  elabo- 
rated sap  from  the  leaves  could  not  descend  below  it. 
A  is  the  top  of  the  nearly  horizontal  branch. 

FIG.  29  shows  how  a  branch  of  a  wild  grape  vine,  after  being  girdled, 
formed  new  wood  from  both  above  and  below,  and  thus  made 
a  new  passage  for  the  downward  flow  of  the  sap.  The  wood 
developed  from  beneath  the  girdle  was  formed  from  sap 
elaborated  in  other  branches. 

FIG.  30  is  a  section  of  the  stem  of  a  young  bass  tre^,  which  shows  that 
when  there  is  no  foliage  below  a  place  girdled  early  in  the 
season,  there  can  be  no  deposition  of  new  wood,  while  it  may 
be  as  abundant  as  usual  above  the  girdle. 

FIG.  31  represents  a  section  of  a  stem  of  a  young  red  maple,  girdled  June 
twenty-third,  which  is  enlarged  above  the  girdle,  but  not  below. 

FIG.  32  exhibits  a  similar  section,  girdled  July  twenty-first,  upon  which 
was  produced  a  new  growth  of  both  wood  and  bark,  which 
resulted  from  the  fact  that  the  cambium  layer  was  so  far 
organized  by  midsummer  as  to  furnish  a  conducting  medium 
for  the  elaborated  sap. 

FIG.  33  shows  the  microscopic  structure  of  the  ordinary  bark  of  a  young 
red  maple. 

A,  periderm  or  cork. 

B,  primary  parenchyma. 

C,  secondary  parenchyma. 

D,  bast  fibres. 

E,  woody  fibre  of  trunk. 

F,  vessels  or  ducts  in  wood. 

G,  medullary  rays  connecting  bark  and  wood. 
H,  recent  parenchyma  of  inner  bark. 


PHENOMENA  OF  PLANT-LIFE.  95 

FIG.  34  represents  the  same  elements  of  the  new  bark  formed  on 
the  place  girdled,  July  twenty-first,  the  periderm  being 
of  a  reddish  brown  color. 

FIG.  35  is  a  view  of  the  section  of  a  weeping  willow  tree,  to  illustrate 
the  mode  of  growth  in  trees  from  which  the  bark  has  been 
loosened  by  freezing. 

A  is  sap-wood  formed  on  the  inside  of  the  bark  and  discon- 
nected from  the  wood  of  the  trunk. 

B  is  new  wood  and  periderm  formed  on  the  old  wood,  to 
which  a  portion  of  the  cambium  cells  remained  attached 
when  the  old  bark  was  torn  off  by  the  frost. 
C,  roots  developed  from  the  uninjured  stem  under  the  old 
disrupted  bark,  and  extending  to  the  earth,  a  distance 
of  more  than  fifteen  inches. 

FIG.  36  exhibits  a  specimen  of  a  pendant  weeping  willow  branch,  which 
was  girdled  in  June  last  The  growth  was  on  the  lower  side 
of  the  girdled  place,  showing  that  the  flow  of  the  elaborated 
sap  is  not  necessarily  downward,  but  roo^-ward. 

FIG.  37  is  a  view  of  a  pistillate  plant  of  mistletoe,  with  evergreen 
coriaceous  leaves  and  white  berries,  growing  on  the  limb  of 
an  oak. 

A  represents  the  parasitic  roots  of  the  mistletoe  in  the  sap- 
wood  of  the  oak.     As  the  oak  was  dead  beyond  the  large 
cluster  of  the  parasite,  it  seems  that  it  was  injured  by  the 
loss  of  its  sap. 
FIG.  38  illustrates  the  natural  grafting  of  two  trunks  of  white  pine. 

A  is  the  smaller  trunk,  a  branch  of  which  is  seen  to  grow 
through  the  wood  of  the  larger  one.     The  union  of  wood 
is   perfect,  and   the   elaborated   sap  from   B  has  flowed 
so  freely  over  the  connecting  branch,  that  A  is  larger 
below,  and  B  larger  above  the  place  of  junction. 
C  is  the  knot  in  the  heart  of  B,  formed  of  the  base  of  the  limb, 
in  the  axil  of  which  D,  the  connecting  branch,  became 
fastened  in  the  beginning  of  the  operation. 
FIG.  39  shows  the  grafted  roots  of   a  white  pine  stump,  the  points  of 

union  being  very  numerous. 

FIG.  40  exhibits  a  section  of  a  small  white  birch  tree,  one  of  whose- 
branches  has  become  grafted  to  it  in  consequence  of  being 
caught  in  the  axil  of  a  branch  above. 

FIG.  41  represents  a  section  of  the  trunk  of  a  small  aspen,  around  which 
a  vine  of  bitter-sweet  has  twined  so  closely  as  to  prevent  the 
root-ward  flow  of  elaborated  sap.  The  growth  therefore 
follows  the  bitter-sweet  in  a  spiral  direction. 

FIG.  42  shows  a  longitudinal  section  of  the  preceding  specimen.  The 
wood  is  seen  to  have  formed  from  above  so  as  to  cover  the 
vine,  while  immediately  below  it  there  has  been  no  growth 
whatever. 

FIG.  43  exhibits  the  dead  wood  of  an  apple  tree  limb,  which  was  depos- 
ited so  that  the  fibres  run  in  a  spiral  direction. 


96  PHENOMENA  OF  PLANT-LIFE. 

FIG.  44  represents  the  variations  of  pressure,  as  indicated  by  the  mercurial 
gauges,  on  the  twenty-first  of  April,  1873,  observations  having 
been  taken  every  hour,  from  twelve  A.  M.,  to  twelve  p.  M. 
Every  vertical  line  marks  an  hour,  and  every  horizontal  line 
an  inch  on  the  column  of  mercury.  Zero  represents  the  point 
where  there  is  neither  pressure  outward  from  the  tree,  nor 
suction  inward. 

The  line  A  shows  the  record  of  the  sugar  maplo,  which  at 
midnight  exhibited  a  suction  equal  to  -6  inches,  and  at  7  A  M. 
had  increased  this  to  -22.9  inches.  As  soon  as  the  sun 
warmed  the  tree,  the  mercury  began  to  rise  and  at  9.15  A.  M., 
had  reached  16.3  inches.  Then  it  declined  very  gradually  till 
at  12  P.  M.  it  was  at  -3  inches.  The  temperature  at  7  A.  M.  was 
37°  F. ;  at  2  P.  M.  was  50.1°  F. ;  and  at  9  P.  M.  it  was  39.5°  F. 

The  line  C  marks  the  fluctuations  of  the  mercury  in  the 
lower  gauge  of  the  black  birch,  which  was  at  the  level  of  the 
ground,  and  the  line  B  shows  the  pressure  in  the  upper  gauge, 
which  was  placed  30.2  feet  above  the  lower  one.  The  remark- 
able fall,  indicated  as  occurring  at  12.45  P.  M.,  was  caused  by 
boring  into  the  tree  near  the  ground  for  the  purpose  of  deter- 
mining whether  the  tree  was  acting  simply  as  a  cylinder  of 
water  filled  by  a  force  from  beneath,  as  seemed  evident  from 
the  correspondence  between  the  two  gauges.  The  reduction 
and  restoration  of  pressure  from  simply  opening  and  closing 
the  orifice  were  so  rapid  and  extraordinary  as  to  lead  to  the 
conclusion  that  the  force  operating  to  produce  the  pressure 
was  simply  the  absorbent  power  of  the  roots,  and  this  led  to 
the  application  of  a  gauge  directly  to  a  root,  with  the  sur- 
prising result  described  on  page  253. 

The  proportion  borne  by  the  cuts  to  the  natural  size  of  the  object 
represented  is  expressed  by  a  fraction  under  the  figure.  Thus,  in  figure 
one,  the  fraction  £  indicates  one-sixth  the  natural  size,  while  in  figure 
three,  the  fraction  *£•  indicates  that  the  object  is  magnified  fifty  times. 


PHENOMENA  OF  PLANT-LIFE. 


97 


98 


PHENOMENA  OF  PLANT-LIFE. 


Fig.  3,  p.  9. 


PHENOMENA  OF  PLANT-LIFE, 


99 


100  PHENOMENA  OF  PLANT-LIFE. 


A. 


B 
Fig.  8,  p.  15 

¥ 


PHENOMENA  OF  PLANT-LIFE. 


101 


102 


PHENOMENA   OF  PLANT-LIFE. 


PHENOMENA  OF  PLANT-LIFE. 


108 


fig.  1G,  p.  20. 

I 


104 


PHENOMENA    OF  PLANT-LIFE 


PHENOMENA  OF  PLANT-LIFE.  105 


Fig.  23,  p.  32. 


106  PHENOMENA   OF  PLANT-LIFE. 


Wig.  24,  p.  33. 


Fly.  25,  p.  33. 
i 


Fig.  26,  p.  33. 


Fig.  28,  p.  30. 


PHENOMENA   OF  PLANT-LIFE. 


107 


Fig.  33,  p.  37.         Fig.  34,  V.  .97 


108 


PHENOMENA  OF  PLANT-LIFE. 


Fig.  36,  p.  40. 
I 


L....C 


ass 

35,  p.  38. 


PHENOMENA  OF  PLANT-LIFE.  109 


110 


PHENOMENA  OF  PLANT-LIFE. 


-A 


Fig.  41.  p.  42. 

A 


Fig.  42,  p.  42. 


Fig.  43,  p.  43, 


t 


PHENOMENA  OF  PLANT-LIFE.  Ill 


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14  DAY  USE 

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iSDtfeiJ* 

; 

JAN  10  1962 

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Wiasttus        ^w.'asLoi. 

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